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Bibliography on: Metagenomics

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ESP: PubMed Auto Bibliography 27 Nov 2020 at 01:31 Created: 

Metagenomics

While genomics is the study of DNA extracted from individuals — individual cells, tissues, or organisms — metagenomics is a more recent refinement that analyzes samples of pooled DNA taken from the environment, not from an individual. Like genomics, metagenomic methods have great potential in many areas of biology, but none so much as in providing access to the hitherto invisible world of unculturable microbes, often estimated to comprise 90% or more of bacterial species and, in some ecosystems, the bulk of the biomass. A recent describes how this new science of metagenomics is beginning to reveal the secrets of our microbial world: The opportunity that stands before microbiologists today is akin to a reinvention of the microscope in the expanse of research questions it opens to investigation. Metagenomics provides a new way of examining the microbial world that not only will transform modern microbiology but has the potential to revolutionize understanding of the entire living world. In metagenomics, the power of genomic analysis is applied to entire communities of microbes, bypassing the need to isolate and culture individual bacterial community members.

Created with PubMed® Query: metagenomic OR metagenomics OR metagenome NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2020-11-26

Claudia S, Marta C, Laia NM, et al (2020)

Antibiotic and antibiotic-resistant gene loads in swine slurries and their digestates: implications for their use as fertilizers in agriculture.

Environmental research pii:S0013-9351(20)31410-9 [Epub ahead of print].

The spread of antibiotic resistance in bacteria is a matter of global concern, and the identification of possible sources of the associated genetic elements (antibiotic resistance genes -ARGs-, components of the horizontal gene transfer mechanism), is becoming an urgent need. While the transmission of ARGs in medical settings have been adequately characterized, ARG propagation in agroecosystems remains insufficiently studied. Particularly crucial is the determination of potential risks associated to the use of swine slurries and related products as component of organic fertilizers, an increasingly used farming practice. We determined ARGs and antibiotic loads analyzed from swine slurries and digestates from eight farms from Catalonia (NE Spain), and compared the results with their microbiome composition. Both ARGs and antibiotic were conspicuous in farm organic wastes, and the levels of some antibiotics exceeded currently accepted minimum inhibitory concentrations. Particularly, the presence of high loads of fluoroquinolones was directly correlated to the prevalence of the related qnrS1 ARG in the slurry. We also found evidence that ARG loads were directly correlated to the prevalence of determined bacterial taxa (Actinobacteria, Proteobacteria, Spirochaeta), a parameter that could be potentially modulated by the processing of the raw slurry prior to their use as fertilizer.

RevDate: 2020-11-26

Zurek PJ, Hours R, Schell U, et al (2020)

Growth amplification in ultrahigh-throughput microdroplet screening increases sensitivity of clonal enzyme assays and minimizes phenotypic variation.

Lab on a chip [Epub ahead of print].

Microfluidic ultrahigh-throughput screening of enzyme activities provides information on libraries with millions of variants in a day. Each individual library member is represented by a recombinant single cell, compartmentalised in an emulsion droplet, in which an activity assay is carried out. Key to the success of this approach is the precision and sensitivity of the assay. Assay quality is most profoundly challenged when initially weak, promiscuous activities are to be enhanced in early rounds of directed evolution or when entirely novel catalysts are to be identified from metagenomic sources. Implementation of measures to widen the dynamic range of clonal assays would increase the chances of finding and generating new biocatalysts. Here, we demonstrate that the assay sensitivity and DNA recovery can be improved by orders of magnitude by growth of initially singly compartmentalised cells in microdroplets. Homogeneous cell growth is achieved by continuous oxygenation and recombinant protein expression is regulated by diffusion of an inducer from the oil phase. Reaction conditions are adjusted by directed droplet coalescence to enable full control of buffer composition and kinetic incubation time, creating level playing field conditions for library selections. The clonal amplification multiplies the product readout because more enzyme is produced per compartment. At the same time, phenotypic variation is reduced by measuring monoclonal populations rather than single cells and recovery efficiency is increased. Consequently, this workflow increases the efficiency of lysate-based microfluidic enzyme assays and will make it easier for protein engineers to identify or evolve new enzymes for applications in synthetic and chemical biology.

RevDate: 2020-11-26

Stockler RM, Higgins KV, Hallowell H, et al (2020)

In vivo Microbiome Profiling of the Luminal and Mucosal Surface of the Duodenum Using a Cannulated Yearling Bovine Model.

Frontiers in veterinary science, 7:601874.

The gut microbiome provides important metabolic functions for the host animal. Bacterial dysbiosis as a result of bacterial, viral, and parasitic gastrointestinal infections can adversely affect the metabolism, productivity, and overall health. The objective of this study is to characterize the commensal microbiome present in the lumen and the mucosal surface of the duodenum of cattle, as we hypothesize that due to metabolic processes and or host proprieties, there are differences in the natural microbiota present in the mucosal surface and luminal contents of the bovine duodenum. Duodenal lumen contents and mucosal biopsies were collected from six dairy crossbred yearling steers. A flexible video-endoscope was used to harvest biopsy samples via a T shaped intestinal cannula. In order to assess as much environmental and individual steer microbiota variation as possible, each animal was sampled three times over a 6 week period. The DNA was extracted from the samples and submitted for16S rRNA gene Ion Torrent PGM bacterial sequencing. A detailed descriptive analysis from phylum to genus taxonomic level was reported. Differences in the microbiome population between two different sites within the duodenum were successfully characterized. A great and significant microbiota diversity was found between the luminal and mucosal biopsy At the phylum taxonomic level, Firmicutes, and Bacteroidetes composed over 80% of the microbiome. Further analysis at lower taxonomic levels, class, family, and genus, showed distinct diversity and distribution of the microbiome. Characterizing the gastrointestinal microbiome in vivo is imperative. The novelty of this study is the use of live cattle undergoing customary husbandry allowing real-time analysis of the duodenum microbiome contributing to the literature with respect to the bovine duodenum microbiome.

RevDate: 2020-11-26

Baldan R, P Sendi (2020)

Precision Medicine in the Diagnosis and Management of Orthopedic Biofilm Infections.

Frontiers in medicine, 7:580671.

Orthopedic biofilm infections are difficult to treat and require a multidisciplinary approach to diagnostics and management. Recent advances in the field include methods to disrupt biofilm, sequencing tools, and antibiotic susceptibility tests for bacteria residing in biofilm. The observation of interclonal differences in biofilm properties of the causative microorganisms, together with considerations of comorbidities and polypharmacy in a growing aging population, calls for a personalized approach to treat these infections. In this article, we highlight aspects of precision medicine that may open new perspectives in the diagnosis and management of orthopedic biofilm infections.

RevDate: 2020-11-26

Porter AF, Pettersson JH, Chang WS, et al (2020)

Novel hepaci- and pegi-like viruses in native Australian wildlife and non-human primates.

Virus evolution, 6(2):veaa064 pii:veaa064.

The Flaviviridae family of positive-sense RNA viruses contains important pathogens of humans and other animals, including Zika virus, dengue virus, and hepatitis C virus. The Flaviviridae are currently divided into four genera-Hepacivirus, Pegivirus, Pestivirus, and Flavivirus-each with a diverse host range. Members of the genus Hepacivirus are associated with an array of animal species, including humans, non-human primates, other mammalian species, as well as birds and fish, while the closely related pegiviruses have been identified in a variety of mammalian taxa, also including humans. Using a combination of total RNA and whole-genome sequencing we identified four novel hepaci-like viruses and one novel variant of a known hepacivirus in five species of Australian wildlife. The hosts infected comprised native Australian marsupials and birds, as well as a native gecko (Gehyra lauta). From these data we identified a distinct marsupial clade of hepaci-like viruses that also included an engorged Ixodes holocyclus tick collected while feeding on Australian long-nosed bandicoots (Perameles nasuta). Distinct lineages of hepaci-like viruses associated with geckos and birds were also identified. By mining the SRA database we similarly identified three new hepaci-like viruses from avian and primate hosts, as well as two novel pegi-like viruses associated with primates. The phylogenetic history of the hepaci- and pegi-like viruses as a whole, combined with co-phylogenetic analysis, provided support for virus-host co-divergence over the course of vertebrate evolution, although with frequent cross-species virus transmission. Overall, our work highlights the diversity of the Hepacivirus and Pegivirus genera as well as the uncertain phylogenetic distinction between.

RevDate: 2020-11-26

Imchen M, Moopantakath J, Kumavath R, et al (2020)

Current Trends in Experimental and Computational Approaches to Combat Antimicrobial Resistance.

Frontiers in genetics, 11:563975.

A multitude of factors, such as drug misuse, lack of strong regulatory measures, improper sewage disposal, and low-quality medicine and medications, have been attributed to the emergence of drug resistant microbes. The emergence and outbreaks of multidrug resistance to last-line antibiotics has become quite common. This is further fueled by the slow rate of drug development and the lack of effective resistome surveillance systems. In this review, we provide insights into the recent advances made in computational approaches for the surveillance of antibiotic resistomes, as well as experimental formulation of combinatorial drugs. We explore the multiple roles of antibiotics in nature and the current status of combinatorial and adjuvant-based antibiotic treatments with nanoparticles, phytochemical, and other non-antibiotics based on synergetic effects. Furthermore, advancements in machine learning algorithms could also be applied to combat the spread of antibiotic resistance. Development of resistance to new antibiotics is quite rapid. Hence, we review the recent literature on discoveries of novel antibiotic resistant genes though shotgun and expression-based metagenomics. To decelerate the spread of antibiotic resistant genes, surveillance of the resistome is of utmost importance. Therefore, we discuss integrative applications of whole-genome sequencing and metagenomics together with machine learning models as a means for state-of-the-art surveillance of the antibiotic resistome. We further explore the interactions and negative effects between antibiotics and microbiomes upon drug administration.

RevDate: 2020-11-26

Mhatre S, Wood JM, Sielaff AC, et al (2020)

Assessing the Risk of Transfer of Microorganisms at the International Space Station Due to Cargo Delivery by Commercial Resupply Vehicles.

Frontiers in microbiology, 11:566412.

Background: With increasing numbers of interplanetary missions, there is a need to establish robust protocols to ensure the protection of extraterrestrial planets being visited from contamination by terrestrial life forms. The current study is the first report comparing the commercial resupply vehicle (CRV) microbiome with the International Space Station (ISS) microbiome to understand the risks of contamination, thus serving as a model system for future planetary missions.

Results: Samples obtained from the internal surfaces and ground support equipment of three CRV missions were subjected to various molecular techniques for microbial diversity analysis. In total, 25 samples were collected with eight defined locations from each CRV mission prior to launch. In general, the internal surfaces of vehicles were clean, with an order of magnitude fewer microbes compared to ground support equipment. The first CRV mission had a larger microbial population than subsequent CRV missions, which were clean as compared to the initial CRV locations sampled. Cultivation assays showed the presence of Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes and members of Ascomycota and Basidiomycota. As expected, shotgun metagenome analyses revealed the presence of more microbial taxa compared to cultivation-based assays. The internal locations of the CRV microbiome reportedly showed the presence of microorganisms capable of tolerating ultraviolet radiation (e.g., Bacillus firmus) and clustered separately from the ISS microbiome.

Conclusions: The metagenome sequence comparison of the CRV microbiome with the ISS microbiome revealed significant differences showing that CRV microbiomes were a negligible part of the ISS environmental microbiome. These findings suggest that the maintenance protocols in cleaning CRV surfaces are highly effective in controlling the contaminating microbial population during cargo transfer to the ISS via the CRV route.

RevDate: 2020-11-26

Doster E, Thomas KM, Weinroth MD, et al (2020)

Metagenomic Characterization of the Microbiome and Resistome of Retail Ground Beef Products.

Frontiers in microbiology, 11:541972.

Ground beef can be a reservoir for a variety of bacteria, including spoilage organisms, and pathogenic foodborne bacteria. These bacteria can exhibit antimicrobial resistance (AMR) which is a public health concern if resistance in pathogens leads to treatment failure in humans. Culture-dependent techniques are commonly used to study individual bacterial species, but these techniques are unable to describe the whole community of microbial species (microbiome) and the profile of AMR genes they carry (resistome), which is critical for getting a holistic perspective of AMR. The objective of this study was to characterize the microbiome and resistome of retail ground beef products labeled as coming from conventional or raised without antibiotics (RWA) production systems. Sixteen ground beef products were purchased from 6 retail grocery outlets in Fort Collins, CO, half of which were labeled as produced from cattle raised conventionally and half of products were from RWA production. Total DNA was extracted and isolated from each sample and subjected to 16S rRNA amplicon sequencing for microbiome characterization and target-enriched shotgun sequencing to characterize the resistome. Differences in the microbiome and resistome of RWA and conventional ground beef were analyzed using the R programming software. Our results suggest that the resistome and microbiome of retail ground beef products with RWA packaging labels do not differ from products that do not carry claims regarding antimicrobial drug exposures during cattle production. The resistome predominantly consisted of tetracycline resistance making up more than 90% of reads mapped to resistance gene accessions in our samples. Firmicutes and Proteobacteria predominated in the microbiome of all samples (69.6% and 29.0%, respectively), but Proteobacteria composed a higher proportion in ground beef from conventionally raised cattle. In addition, our results suggest that product management, such as packaging type, could exert a stronger influence on the microbiome than the resistome in consumer-ready products. Metagenomic analyses of ground beef is a promising tool to investigate community-wide shifts in retail ground beef. Importantly, however, results from metagenomic sequencing must be carefully considered in parallel with traditional methods to better characterize the risk of AMR in retail products.

RevDate: 2020-11-26

Ateba TP, Alayande KA, M Mwanza (2020)

Feces Metagenomes and Metagenome-Assembled Genome Sequences from Two Separate Dogs (Canis lupus familiaris) with Multiple Diarrheal Episodes.

Microbiology resource announcements, 9(48):.

This study reports two feces metagenomes (D84 and D85) and six metagenome-assembled genomes (MAGs). The assembled MAGs include Pseudomonas sp. strain NID84 and Acinetobacter sp. strain N2D84 from D84 and Enterococcus sp. strain N4D85, Enterococcus sp. strain N5D85, Lactobacillus sp. strain N6D85, and Leuconostoc sp. strain N7D85 from D85. Acinetobacter sp. N2D84 was identified as a human pathogen with a probability of 92%.

RevDate: 2020-11-26

Baker JL, Morton JT, Dinis M, et al (2020)

Deep metagenomics examines the oral microbiome during dental caries, revealing novel taxa and co-occurrences with host molecules.

Genome research pii:gr.265645.120 [Epub ahead of print].

Dental caries, the most common chronic infectious disease worldwide, has a complex etiology involving the interplay of microbial and host factors that are not completely understood. In this study, the oral microbiome, and 38 host cytokines and chemokines, were analyzed across 23 children with caries and 24 children with healthy dentition. De novo assembly of metagenomic sequencing obtained 527 metagenome-assembled genomes (MAGs), representing 150 bacterial species. 42 of these species had no genomes in public repositories, therefore representing novel taxa. These new genomes greatly expanded the known pangenomes of many oral clades, including the enigmatic Saccharibacteria clades G3 and G6, which had distinct functional repertoires compared to other oral Saccharibacteria. Saccharibacteria are understood to be obligate epibionts, which are dependent on host bacteria. This data suggests that the various Saccharibacteria clades may rely on their hosts for highly distinct metabolic requirements, which would have significant evolutionary and ecological implications. Across the study group, Rothia, Neisseria, and Haemophilus spp were associated with good dental health, while Prevotella spp., Streptococcus mutans, and Human herpesvirus 4 (Epstein-barr virus/EBV) were more prevalent in children with caries. Finally, ten of the host immunological markers were significantly elevated in the caries group, and co-occurrence analysis provided an atlas of potential relationships between microbes and host immunological molecules. Overall, this study illustrated the oral microbiome at an unprecedented resolution, and contributed several leads for further study that will increase the understanding of caries pathogenesis and guide therapeutic development.

RevDate: 2020-11-26

Liu F, Zhang Y, Liang H, et al (2020)

Resilience of methane cycle and microbial functional genes to drought and flood in an alkaline wetland: A metagenomic analysis.

Chemosphere pii:S0045-6535(20)33231-8 [Epub ahead of print].

Alkaline wetlands distributed in arid or semi-arid areas are hotspots of methane (CH4) emissions. Periods of drought and flood, although regular, are stressful events encountered by methanogenic anaerobes in alkaline wetlands. To investigate the response of the CH4 cycle of alkaline wetlands to such stresses, we take Zhalong wetland as an example, then determined the CH4 flux and soil microbiomes in the wetland during wet, dry, and flooded periods. The in-situ CH4 flux in the wet period was 9.55-17.29 mg‧m-2‧h-1, but sharply degraded to 3.37-6.61 mg‧m-2‧h-1 in the dry period. It resumed to 4.51-20.80 mg‧m-2‧h-1 when the wetland was flooded again, which indicated that methanogenesis is quite resilient to drought. Syntrophic acetogenesis, and subsequently aceticlastic methanogenesis, were the dominant methanogenic pathways and resisted drought. Members belonging to Syntrophobacterales were the dominant syntrophic acetogens. They enter a viable but non-culturable (VBNC) state to resist drought. The dominant Methanosarcinales have the ability to repair reactive oxygen species damage during dry periods. The community of CH4 sink was governed by anaerobic methanotrophs, which entered a VBNC state or used repair systems to survive dry periods. This study revealed the responses of the CH4 cycle and microbial functional genes to drought and flood in alkaline wetlands.

RevDate: 2020-11-26

Ogawa T, Okumura R, Nagano K, et al (2020)

Oral intake of silica nanoparticles exacerbates intestinal inflammation.

Biochemical and biophysical research communications pii:S0006-291X(20)32091-X [Epub ahead of print].

Nanoparticles, i.e., particles with a diameter of ≤100 nm regardless of their composing material, are added to various foods as moisturizers, coloring agents, and preservatives. Silicon dioxide (SiO2, silica) nanoparticles in particular are widely used as food additives. However, the influence of SiO2 nanoparticle oral consumption on intestinal homeostasis remains unclear. The daily intake of 10-nm-sized SiO2 nanoparticles exacerbates dextran sulfate sodium (DSS)-induced colitis, whereas the daily intake of 30-nm-sized SiO2 nanoparticles has no influence on intestinal inflammation. The exacerbation of colitis induced by consuming 10-nm-sized SiO2 nanoparticles was abolished in mice deficient in apoptosis-associated speck-like protein containing a CARD (ASC). Our study indicates that the oral intake of small SiO2 nanoparticles poses a risk for worsening intestinal inflammation through activation of the ASC inflammasome.

RevDate: 2020-11-26

Kuge T, Fukushima K, Matsumoto Y, et al (2020)

Pulmonary disease caused by a newly identified mycobacterium: Mycolicibacterium toneyamachuris: a case report.

BMC infectious diseases, 20(1):888 pii:10.1186/s12879-020-05626-y.

BACKGROUND: Non-tuberculous mycobacterial pulmonary disease (NTM-PD) is becoming a significant health burden. Recent advances in analysis techniques have allowed the accurate identification of previously unknown NTM species. Here, we report a case of NTM-PD caused by a newly identified mycobacteria in an immunocompetent patient.

CASE PRESENTATION: A 44-year-old woman was referred to our hospital due to the frequent aggravation of her chronic respiratory symptoms, with NTM-PD-compatible computed tomography findings. Unidentified mycobacterium was repeatedly isolated from respiratory specimens and we diagnosed her as NTM-PD of unidentified mycobacterium. Subsequent whole-genome analysis revealed that the unidentified mycobacterium was a novel mycobacterium genetically close to Mycolicibacterium mucogenicum. We started combination therapy with clarithromycin, moxifloxacin, amikacin, and imipenem/cilastatin, referring to drug sensitivity test results and observed its effect on M. mucogenicum infection. Her symptoms and radiological findings improved significantly.

CONCLUSION: We report a case of NTM-PD caused by a newly identified mycobacteria, Mycolicibacterium toneyamachuris, genetically close to M. mucogenicum. This pathogenic mycobacterium showed different characteristics from M. mucogenicum about clinical presentation and drug sensitivity. The clinical application of genomic sequencing will advance the identification and classification of pathogenic NTM species, and enhance our understanding of mycobacterial diseases.

RevDate: 2020-11-26

Zhang X, Wu Z, K Wang (2020)

Diagnosis of Streptococcus suis Meningoencephalitis with metagenomic next-generation sequencing of the cerebrospinal fluid: a case report with literature review.

BMC infectious diseases, 20(1):884 pii:10.1186/s12879-020-05621-3.

BACKGROUND: Streptococcus suis meningoencephalitis is a zoonotic disease that mostly infects slaughterhouse workers. Rapid diagnosis of Streptococcus suis meningoencephalitis is critical for effective clinical management of this condition. However, the current diagnostic techniques are not effective for early diagnosis of this condition. To the best of our knowledge, the use of cerebrospinal fluid metagenomic next generation sequencing in the diagnosis of Streptococcus suis meningoencephalitis has been rarely reported.

CASE PRESENTATION: Here, we report a case of Streptococcus suis meningoencephalitis in a 51-year-old female patient. The patient had a history of long-term contact with pork and had a three-centimeter-long wound on her left leg prior to disease onset. Conventional tests, including blood culture, gram staining and cerebrospinal fluid culture, did not reveal bacterial infection. However, Streptococcus suis was detected in cerebrospinal fluid using metagenomic next generation sequencing.

CONCLUSIONS: Metagenomic next generation sequencing is a promising approach for early diagnosis of central nervous system infections. This case report indicates that cases of clinical meningeal encephalitis of unknown cause can be diagnosed through this method.

RevDate: 2020-11-26

Au CC, Hon KL, Leung AKC, et al (2020)

Childhood Infectious Encephalitis: An Overview of Clinical Features, Investigations, Treatment and Recent Patents.

Recent patents on inflammation & allergy drug discovery pii:IAD-EPUB-111791 [Epub ahead of print].

BACKGROUND: Infectious encephalitis is a serious and challenging condition to manage. This overview summarizes the current literature regarding the etiology, clinical manifestations, diagnosis, management and recent patents of acute childhood infectious encephalitis.

METHODS: We used PubMed Clinical Queries and keywords of "encephalitis" AND "childhood" as a search engine, and patents were searched using the key term "encephalitis" in google.patents.com and patentsonline.com.

RESULTS: Viral encephalitis is the most common cause of acute infectious encephalitis in children. In young children, the clinical manifestations can be non-specific. Provision of empiric antimicrobial therapy until a specific infectious organism has been identified, which in most cases includes acyclovir, is the cornerstone of therapy. Advanced investigation tools, including nucleic acid-based test panel and metagenomic next generation sequencing, improve diagnostic yield of identifying an infectious organism. Supportive therapy includes adequate airway and oxygenation, fluid and electrolyte balance, and cerebral perfusion pressure support and seizure control. Recent patents are related to diagnosis, treatment and prevention of acute infectious encephalitis.

CONCLUSIONS: Viral encephalitis is the most common cause of acute infectious encephalitis in children and is associated with significant morbidity. Recent advances in understanding the genetic basis and immunological correlation of infectious encephalitis may improve treatment. Third-tier diagnostic tests may be incorporated into clinical practice. Treatment is targeted at the infectious process but remains mostly supportive. Specific antimicrobial agents and vaccines development is ongoing.

RevDate: 2020-11-26

Zhang X, Zhao A, Sandhu AK, et al (2020)

Functional Deficits in Gut Microbiome of Young and Middle-Aged Adults with Prediabetes Apparent in Metabolizing Bioactive (Poly)phenols.

Nutrients, 12(11): pii:nu12113595.

BACKGROUND: Gut microbiota metabolize select dietary (poly)phenols to absorbable metabolites that exert biological effects important in metabolic health. Microbiota composition associated with health/disease status may affect its functional capacity to yield bioactive metabolites from dietary sources. Therefore, this study assessed gut microbiome composition and its related functional capacity to metabolize fruit (poly)phenols in individuals with prediabetes and insulin resistance (PreDM-IR, n = 26) compared to a metabolically healthy Reference group (n = 10).

METHODS: Shotgun sequencing was used to characterize gut microbiome composition. Targeted quantitative metabolomic analyses of plasma and urine collected over 24 h were used to assess microbial-derived metabolites in response to a (poly)phenol-rich raspberry test drink.

RESULTS: PreDM-IR compared to the Reference group: (1) enriched Blautia obeum and Blautia wexlerae and depleted Bacteroides dorei and Coprococcus eutactus. Akkermansia muciniphila and Bacteroides spp. were depleted in the lean PreDM-IR subset; and (2) impaired microbial catabolism of select (poly)phenols resulting in lower 3,8-dihydroxy-urolithin (urolithin A), phenyl-γ-valerolactones and various phenolic acids concentrations (p < 0.05). Controlling for obesity revealed relationships with microbial species that may serve as metagenomic markers of diabetes development and therapeutic targets.

CONCLUSIONS: Data provide insight from multi-omics approaches to advance knowledge at the diet-gut-disease nexus serving as a platform for devising dietary strategies to improve metabolic health.

RevDate: 2020-11-26

Woerther PL, d'Humières C, Lescure X, et al (2020)

Is the term "anti-anaerobic" still relevant?.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 102:178-180 pii:S1201-9712(20)32256-6 [Epub ahead of print].

For decades, the term "anti-anaerobic" has been commonly used to refer to antibiotics exhibiting activity against anaerobic bacteria, also designated as anaerobes. This term is used in various situations ranging from infections associated with well-identified pathogens like Clostridioides difficile, or Fusobacterium necrophorum in Lemierre's syndrome, that require specific antibiotic treatments to polymicrobial infections generally resulting from the decreased permeability of anatomical barriers (e.g., intestinal translocation and stercoral peritonitis) or infectious secondary localizations (e.g., brain abscess and infectious pleurisy). In these cases, the causal bacteria generally remain unidentified and the antimicrobial treatment is empirical. However, major progress in the knowledge of human bacterial microbiotas in the last 10 years has shown how diverse are the species involved in these communities. Here, we sought to reappraise the concept of anti-anaerobic spectrum in the light of recent advances in the microbiota field. We first highlight that the term anaerobic itself does not represent the tremendous diversity of the bacteria it spans, and then we stress that the antibiotic susceptibility profiles for most anaerobic bacteria remain unaddressed. Furthermore, we provide examples challenging the relevance of the "anti-anaerobic" spectrum from a clinical and ecological perspective.

RevDate: 2020-11-25

Wang X, Hu K, Xu Q, et al (2020)

Immobilization of Cd Using Mixed Enterobacter and Comamonas Bacterial Reagents in Pot Experiments with Brassica rapa L.

Environmental science & technology [Epub ahead of print].

Enterobacter sp. A11 and Comamonas sp. A23 were isolated and identified. Coculturing these two strains with Cd(II) led to the production of biofilm, H2S, and succinic acid (SA), and Cd(II) was adsorbed by cells and formed CdS precipitates. After centrifugation, 97% Cd(II) was removed from the coculture. Proteomic and metabolomic analyses of the cocultured bacteria revealed that H2S and SA production pathways, metal transportation, and TCA cycle were active under Cd(II) stress. In vitro addition of SA enhanced the production of H2S and biofilm formation and Cd(II) adsorption. Two-season greenhouse pot experiments with Brassica rapa L. were performed with and without the coculture bacteria. Compared with the control, the average Cd amounts of the two-season pot experiments of the aboveground plants were decreased by 71.3%, 62.8%, and 38.6%, and the nonbioavailable and immobilized Cd in the soils were increased by 211.8%, 213.4%, and 116.7%, for low-, medium-, and high- Cd-spiked soils, respectively. The two strains survived well in soil during plant growth using plate counting, quantitative real-time PCR, and metagenomics analysis. Our results indicate that the combination of Enterobacter and Comamonas strains with the production of H2S and biofilm are important effectors for the highly efficient immobilization of Cd.

RevDate: 2020-11-25

Wang YH, Wu YH, Luo LW, et al (2020)

Metagenomics analysis of the key functional genes related to biofouling aggravation of reverse osmosis membranes after chlorine disinfection.

Journal of hazardous materials pii:S0304-3894(20)32592-9 [Epub ahead of print].

Chlorine disinfection is a common technology to control biofouling in the pretreatment of the reverse osmosis (RO) system for wastewater reclamation. However, chlorine disinfection could even aggravate the RO membrane biofouling because of the changes of microbial community structure. In this study, the mechanism of biofilm formation and EPS secretion after chlorine disinfection was investigated by analyzing the genes coding quorum sensing, exopolysaccharide biosynthesis, and amino acid biosynthesis. After 1, 5, and 15 mg-Cl2/L chlorine disinfection, the relative abundances of the functional genes all increased significantly. Compared with the control group, chlorine-resistant bacteria (Acidovorax, Arenimonas, and Pseudomonas) also harbored higher relative abundances of these functional genes. The high relative abundances of these genes might provide the bacterial community after chlorine disinfection with high potential of biofilm formation and EPS secretion and then cause severe RO membrane biofouling. In the sample with 5 mg-Cl2/L chlorine disinfection, the correlation coefficients (r) between each two of the three kinds of functional genes were more than 0.9 and much stronger than that in the control group. These results indicated that the bacterial community selected by chlorine disinfection could build more stable biofilm to resist chlorine but also could cause more severe RO membrane biofouling.

RevDate: 2020-11-25

Hewson I, Aquino CA, CM DeRito (2020)

Virome Variation during Sea Star Wasting Disease Progression in Pisaster ochraceus (Asteroidea, Echinodermata).

Viruses, 12(11): pii:v12111332.

Sea star wasting disease (SSWD) is a condition that has affected asteroids for over 120 years, yet mechanistic understanding of this wasting etiology remains elusive. We investigated temporal virome variation in two Pisaster ochraceus specimens that wasted in the absence of external stimuli and two specimens that did not experience SSWD for the duration of our study, and compared viromes of wasting lesion margin tissues to both artificial scar margins and grossly normal tissues over time. Global assembly of all SSWD-affected tissue libraries resulted in 24 viral genome fragments represented in >1 library. Genome fragments mostly matched densoviruses and picornaviruses with fewer matching nodaviruses, and a sobemovirus. Picornavirus-like and densovirus-like genome fragments were most similar to viral genomes recovered in metagenomic study of other marine invertebrates. Read recruitment revealed only two picornavirus-like genome fragments that recruited from only SSWD-affected specimens, but neither was unique to wasting lesions. Wasting lesion margin reads recruited to a greater number of viral genotypes (i.e., richness) than did either scar tissue and grossly normal tissue reads. Taken together, these data suggest that no single viral genome fragment was associated with SSWD. Rather, wasting lesion margins may generally support viral proliferation.

RevDate: 2020-11-25

Horne RG, Yu Y, Zhang R, et al (2020)

High Fat-High Fructose Diet-Induced Changes in the Gut Microbiota Associated with Dyslipidemia in Syrian Hamsters.

Nutrients, 12(11): pii:nu12113557.

Aim: The objective of this study was to characterize the early effects of high fructose diets (with and without high fat) on both the composition of the gut microbiota and lipid metabolism in Syrian hamsters, a reproducible preclinical model of diet-induced dyslipidemia. Methods: Eight-week-old male hamsters were fed diets consisting of high-fat/high-fructose, low-fat/high-fructose or a standard chow diet for 14 days. Stool was collected at baseline (day 0), day 7 and day 14. Fasting levels of plasma triglycerides and cholesterol were monitored on day 0, day 7 and day 14, and nonfasting levels were also assayed on day 15. Then, 16S rRNA sequencing of stool samples was used to determine gut microbial composition, and predictive metagenomics was performed to evaluate dietary-induced shifts in deduced microbial functions. Results: Both high-fructose diets resulted in divergent gut microbiota composition. A high-fat/high-fructose diet induced the largest shift in overall gut microbial composition, with dramatic shifts in the Firmicute/Bacteroidetes ratio, and changes in beta diversity after just seven days of dietary intervention. Significant associations between genus level taxa and dietary intervention were identified, including an association with Ruminococceace NK4A214 group in high-fat/high-fructose fed animals and an association with Butryimonas with the low-fat/high-fructose diet. High-fat/high-fructose feeding induced dyslipidemia with increases in plasma triglycerides and cholesterol, and hepatomegaly. Dietary-induced changes in several genus level taxa significantly correlated with lipid levels over the two-week period. Differences in microbial metabolic pathways between high-fat/high-fructose and low-fat/high-fructose diet fed hamsters were identified, and several of these pathways also correlated with lipid profiles in hamsters. Conclusions: The high-fat/high-fructose diet caused shifts in the host gut microbiota. These dietary-induced alterations in gut microbial composition were linked to changes in the production of secondary metabolites, which contributed to the development of metabolic syndrome in the host.

RevDate: 2020-11-25

Estrada-Peña A, Cabezas-Cruz A, D Obregón (2020)

Behind Taxonomic Variability: The Functional Redundancy in the Tick Microbiome.

Microorganisms, 8(11): pii:microorganisms8111829.

The taxonomic composition and diversity of tick midgut microbiota have been extensively studied in different species of the genera Rhipicephalus, Ixodes, Amblyomma, Haemaphysalis, Hyalomma, Dermacentor, Argas and Ornithodoros, while the functional significance of bacterial diversity has been proportionally less explored. In this study, we used previously published 16S amplicon sequence data sets from three Ixodes scapularis cohorts, two of uninfected nymphs, and one of larvae experimentally infected with Borrelia burgdorferi, to test the functional redundancy of the tick microbiome. We predicted the metabolic profiling of each sample using the state-of-the-art metagenomics tool PICRUSt2. The results showed that the microbiomes of all I. scapularis samples share only 80 taxa (24.6%, total 324), while out of the 342 metabolic pathways predicted, 82.7%, were shared by all the ticks. Borrelia-infected larvae lack 15.4% of pathways found in the microbiome of uninfected nymphs. Taxa contribution analysis showed that the functional microbiome of uninfected ticks was highly redundant, with, in some cases, up to 198 bacterial taxa contributing to a single pathway. However, Borrelia-infected larvae had a smaller redundancy with 6.7% of pathways provided by more than 100 genera, while 15.7-19.2% of pathways were provided by more than 100 genera in the two cohorts of uninfected ticks. In addition, we compared the functional profiles of three microbial communities from each data set, identified through a network-based approach, and we observed functional similarity between them. Based on the functional redundancy and functional similarity of the microbiome of ticks in different developmental stages and infection status, we concluded that the tick gut microbiota is a self-regulating community of very diverse bacteria contributing to a defined set of metabolic pathways and functions with yet unexplored relevance for tick fitness and/or bacterial community stability. We propose a change of focus in which the tick microbiome must be analyzed in all dimensions, highlighting their functional traits, instead of the conventional taxonomic profiling.

RevDate: 2020-11-25

Santiago-Rodriguez TM, Garoutte A, Adams E, et al (2020)

Metagenomic Information Recovery from Human Stool Samples Is Influenced by Sequencing Depth and Profiling Method.

Genes, 11(11): pii:genes11111380.

Sequencing of the 16S rRNA gene (16S) has long been a go-to method for microbiome characterization due to its accessibility and lower cost compared to shotgun metagenomic sequencing (SMS). However, 16S sequencing rarely provides species-level resolution and cannot provide direct assessment of other taxa (e.g., viruses and fungi) or functional gene content. Shallow shotgun metagenomic sequencing (SSMS) has emerged as an approach to bridge the gap between 16S sequencing and deep metagenomic sequencing. SSMS is cost-competitive with 16S sequencing, while also providing species-level resolution and functional gene content insights. In the present study, we evaluated the effects of sequencing depth on marker gene-mapping- and alignment-based annotation of bacteria in healthy human stool samples. The number of identified taxa decreased with lower sequencing depths, particularly with the marker gene-mapping-based approach. Other annotations, including viruses and pathways, also showed a depth-dependent effect on feature recovery. These results refine the understanding of the suitability and shortcomings of SSMS, as well as annotation tools for metagenomic analyses in human stool samples. Results may also translate to other sample types and may open the opportunity to explore the effect of sequencing depth and annotation method.

RevDate: 2020-11-25

Yasir M, Bibi F, Hashem AM, et al (2020)

Comparative metagenomics and characterization of antimicrobial resistance genes in pasteurized and homemade fermented Arabian laban.

Food research international (Ottawa, Ont.), 137:109639.

The aim of this study was to investigate bacterial diversity and function in a fermented milk drink called laban, which is traditionally served in the Middle East, Africa, and Indian subcontinent. Pasteurized laban (LBP) and unpasteurized, homemade, raw laban (LBR) underwent 16S rRNA gene amplicon and shotgun sequencing to analyze their bacterial community, presence of antimicrobial resistance genes (ARGs), and metabolic pathways. This study highlighted relatively greater diversity in LBR bacterial populations compared to LBP, despite containing similar major taxa that consisted primarily of Firmicutes followed by Proteobacteria, Bacteroidetes, and Actinobacteria. The dominant species, Streptococcus thermophilus, was relatively more abundant in LBP (80.7%) compared to LBR (47.9%). LBR had increased diversity and higher relative abundance of several known probiotic bacteria, such as Streptococcus salivarius and Lactococcus lactis, whereas Lactobacillus acidophilus was detected at a higher abundance in LBP. Pathogens like Acinetobacter baumannii, Streptococcus pneumoniae, Streptococcus pyogenes, and Escherichia coli had lower abundance in LBP compared to LBR. Thirty-three ARGs were detected in LBR compared to nine in LBP and are responsible for resistance to 11 classes of antibiotics. A significant proportion of the metagenomes from both types of laban were assigned to housekeeping functions, such as amino acid metabolism, translation, membrane transport, and carbohydrate metabolism. LBR demonstrated increased diversity in probiotics and metabolic functions compared to LBP. However, the relatively high diversity of pathogenic and opportunistic bacteria and ARGs in LBR raises safety concerns and highlights the need for a more hygienic environment for the processing of homemade fermented dairy foods.

RevDate: 2020-11-25
CmpDate: 2020-11-25

Jalili V, Afgan E, Gu Q, et al (2020)

The Galaxy platform for accessible, reproducible and collaborative biomedical analyses: 2020 update.

Nucleic acids research, 48(W1):W395-W402.

Galaxy (https://galaxyproject.org) is a web-based computational workbench used by tens of thousands of scientists across the world to analyze large biomedical datasets. Since 2005, the Galaxy project has fostered a global community focused on achieving accessible, reproducible, and collaborative research. Together, this community develops the Galaxy software framework, integrates analysis tools and visualizations into the framework, runs public servers that make Galaxy available via a web browser, performs and publishes analyses using Galaxy, leads bioinformatics workshops that introduce and use Galaxy, and develops interactive training materials for Galaxy. Over the last two years, all aspects of the Galaxy project have grown: code contributions, tools integrated, users, and training materials. Key advances in Galaxy's user interface include enhancements for analyzing large dataset collections as well as interactive tools for exploratory data analysis. Extensions to Galaxy's framework include support for federated identity and access management and increased ability to distribute analysis jobs to remote resources. New community resources include large public servers in Europe and Australia, an increasing number of regional and local Galaxy communities, and substantial growth in the Galaxy Training Network.

RevDate: 2020-11-25
CmpDate: 2020-11-25

Nagpal S, Singh R, Yadav D, et al (2020)

MetagenoNets: comprehensive inference and meta-insights for microbial correlation networks.

Nucleic acids research, 48(W1):W572-W579.

Microbial association networks are frequently used for understanding and comparing community dynamics from microbiome datasets. Inferring microbial correlations for such networks and obtaining meaningful biological insights, however, requires a lengthy data management workflow, choice of appropriate methods, statistical computations, followed by a different pipeline for suitably visualizing, reporting and comparing the associations. The complexity is further increased with the added dimension of multi-group 'meta-data' and 'inter-omic' functional profiles that are often associated with microbiome studies. This not only necessitates the need for categorical networks, but also integrated and bi-partite networks. Multiple options of network inference algorithms further add to the efforts required for performing correlation-based microbiome interaction studies. We present MetagenoNets, a web-based application, which accepts multi-environment microbial abundance as well as functional profiles, intelligently segregates 'continuous and categorical' meta-data and allows inference as well as visualization of categorical, integrated (inter-omic) and bi-partite networks. Modular structure of MetagenoNets ensures logical flow of analysis (inference, integration, exploration and comparison) in an intuitive and interactive personalized dashboard driven framework. Dynamic choice of filtration, normalization, data transformation and correlation algorithms ensures, that end-users get a one-stop solution for microbial network analysis. MetagenoNets is freely available at https://web.rniapps.net/metagenonets.

RevDate: 2020-11-25
CmpDate: 2020-11-25

Leidenfrost RM, Pöther DC, Jäckel U, et al (2020)

Benchmarking the MinION: Evaluating long reads for microbial profiling.

Scientific reports, 10(1):5125.

Nanopore based DNA-sequencing delivers long reads, thereby simplifying the decipherment of bacterial communities. Since its commercial appearance, this technology has been assigned several attributes, such as its error proneness, comparatively low cost, ease-of-use, and, most notably, aforementioned long reads. The technology as a whole is under continued development. As such, benchmarks are required to conceive, test and improve analysis protocols, including those related to the understanding of the composition of microbial communities. Here we present a dataset composed of twelve different prokaryotic species split into four samples differing by nucleic acid quantification technique to assess the specificity and sensitivity of the MinION nanopore sequencer in a blind study design. Taxonomic classification was performed by standard taxonomic sequence classification tools, namely Kraken, Kraken2 and Centrifuge directly on reads. This allowed taxonomic assignments of up to 99.27% on genus level and 92.78% on species level, enabling true-positive classification of strains down to 25,000 genomes per sample. Full genomic coverage is achieved for strains abundant as low as 250,000 genomes per sample under our experimental settings. In summary, we present an evaluation of nanopore sequence processing analysis with respect to microbial community composition. It provides an open protocol and the data may serve as basis for the development and benchmarking of future data processing pipelines.

RevDate: 2020-11-25
CmpDate: 2020-11-25

Xu P, Shi Y, Liu P, et al (2020)

16S rRNA gene sequencing reveals an altered composition of the gut microbiota in chickens infected with a nephropathogenic infectious bronchitis virus.

Scientific reports, 10(1):3556.

Infectious bronchitis virus (IBV), a member of the Coronaviridae family, causes serious losses to the poultry industry. Intestinal microbiota play an important role in chicken health and contribute to the defence against colonization by invading pathogens. The aim of this study was to investigate the link between the intestinal microbiome and nephropathogenic IBV (NIBV) infection. Initially, chickens were randomly distributed into 2 groups: the normal group (INC) and the infected group (IIBV). The ilea were collected for morphological assessment, and the ileal contents were collected for 16S rRNA gene sequencing analysis. The results of the IIBV group analyses showed a significant decrease in the ratio of villus height to crypt depth (P < 0.05), while the goblet cells increased compared to those in the INC group. Furthermore, the microbial diversity in the ilea decreased and overrepresentation of Enterobacteriaceae and underrepresentation of Chloroplast and Clostridia was found in the NIBV-infected chickens. In conclusion, these results showed that the significant separation of the two groups and the characterization of the gut microbiome profiles of the chickens with NIBV infection may provide valuable information and promising biomarkers for the diagnosis of this disease.

RevDate: 2020-11-24

Yan X, He M, Zheng J, et al (2020)

Tris (1,3-dichloro-2-propyl) phosphate exposure disrupts the gut microbiome and its associated metabolites in mice.

Environment international, 146:106256 pii:S0160-4120(20)32211-X [Epub ahead of print].

BACKGROUND: Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) has been frequently detected in environmental media and biological samples. However, knowledge of its adverse health consequences is limited, and its impacts on the human gut microbiota, which play a key role in health and disease, remain unexplored.

OBJECTIVES: To better evaluate the potential risk of TDCIPP exposure in human health, we investigated the effects of TDCIPP on gut microbiome and gut metabolites in C57BL/6 mice.

METHODS: We applied an integrated analytical approach by combing 16S rRNA gene sequencing, metagenomic sequencing and 1H NMR metabolomics analysis in fecal samples collected from mouse with TDCIPP exposure as well as those from controls.

RESULTS: Both 16S rRNA sequencing and metagenome sequencing showed that TDCIPP exposure significantly changed the gut microbiome, with a remarkable increased Firmicutes at the expense of Bacteroidetes after exposure. Perturbed gut metabolic profiles in the treated group were also observed and closely related with altered gut microbiome. Gene functional annotation analysis further suggested perturbed gut metabolites could be directly caused by altered gut microbiome.

CONCLUSION: TDCIPP exposure has great influence on the gut ecosystem as reflected by perturbation of microbiome community structure, microbial species, gut microbe associated gene expression and gut metabolites, which may contribute to the progression of certain uncharacterized gut microbiota related host diseases. Our findings provide novel insights into adverse effects of TDCIPP exposure on human health.

RevDate: 2020-11-24

Wang Q, Rogers MJ, Ng SS, et al (2020)

Fixed nitrogen removal mechanisms associated with sulfur cycling in tropical wetlands.

Water research, 189:116619 pii:S0043-1354(20)31154-4 [Epub ahead of print].

Wetland ecosystems play an important role in nitrogen cycling, yet the role of anaerobic ammonium oxidation (anammox) in tropical wetlands remains unclear. In the current study the anammox process accounted for 29.8 ~ 57.3% of nitrogen loss in ex situ activity batch tests of microcosms established from anoxic sediments of different tropical wetlands, with the highest activity being 17.95±0.51 nmol-N/g dry sediment/h. This activity was most likely driven by sulfide oxidation with dissimilatory nitrate reduction to ammonium (sulfide-driven DNRA). Microbial community analyses revealed a variety of anammox bacteria related to several known lineages, including Candidatus Anammoximicrobium, Candidatus Brocadia and Candidatus Kuenenia, at different wetlands. Metagenome predictions, batch tests, and isotope-tracing suggested that the high level of anammox activity was due to sulfide-driven DNRA. This was corroborated by a strong correlation (through Pearson's analysis) between the abundance of anammox bacteria and the nrfA (a dissimilatory nitrate reduction to ammonium gene) and dsrA (a sulfate reductase gene) genes, as well as sulfate, ammonium and nitrate concentrations. These correlations suggest syntrophic interactions among sulfate-reducing, sulfide-driven DNRA, and anammox bacterial populations. A better understanding of the role of sulfur in nitrogen loss via the anammox reaction in natural systems could inform development of a viable wastewater treatment strategy that utilizes sulfate to minimize the activity of denitrifying bacteria and thus to reduce nitrous oxide emissions from wastewater treatment plants.

RevDate: 2020-11-24

Kutilova I, Medvecky M, Leekitcharoenphon P, et al (2020)

Extended-spectrum beta-lactamase-producing Escherichia coli and antimicrobial resistance in municipal and hospital wastewaters in Czech Republic: culture-based and metagenomic approaches.

Environmental research pii:S0013-9351(20)31384-0 [Epub ahead of print].

Wastewaters serve as important hot spots for antimicrobial resistance and monitoring can be used to analyse the abundance and diversity of antimicrobial resistance genes at the level of large bacterial and human populations. In this study, whole genome sequencing of beta-lactamase-producing Escherichia coli and metagenomic analysis of whole-community DNA were used to characterize the occurrence of antimicrobial resistance in hospital, municipal and river waters in the city of Brno (Czech Republic). Cefotaxime-resistant E. coli were mainly extended-spectrum beta-lactamase (ESBL) producers (95.6%, n=158), of which the majority carried blaCTX-M (98.7%; n=151) and were detected in all water samples except the outflow from hospital wastewater treatment plant. A wide phylogenetic diversity was observed among the sequenced E. coli (n=78) based on the detection of 40 sequence types and single nucleotide polymorphisms (average number 34,666 ± 15,710) between strains. The metagenomic analysis revealed a high occurrence of bacterial genera with potentially pathogenic members, including Pseudomonas, Escherichia, Klebsiella, Aeromonas, Enterobacter and Arcobacter (relative abundance > 50%) in untreated hospital and municipal wastewaters and predominance of environmental bacteria in treated and river waters. Genes encoding resistance to aminoglycosides, beta-lactams, quinolones and macrolides were frequently detected, however blaCTX-M was not found in this dataset which may be affected by insufficient sequencing depth of the samples. The study pointed out municipal treated wastewater as a possible source of multi-drug resistant E. coli and antimicrobial resistance genes for surface waters. Moreover, the combination of two different approaches provided a more holistic view on antimicrobial resistance in water environments. The culture-based approach facilitated insight into the dynamics of ESBL-producing E. coli and the metagenomics shows abundance and diversity of bacteria and antimicrobial resistance genes vary across water sites.

RevDate: 2020-11-24

Ilett EE, Jørgensen M, Noguera-Julian M, et al (2020)

Associations of the gut microbiome and clinical factors with acute GVHD in allogeneic HSCT recipients.

Blood advances, 4(22):5797-5809.

Acute graft-versus-host disease (aGVHD) is a leading cause of transplantation-related mortality after allogeneic hematopoietic stem cell transplantation (aHSCT). 16S ribosomal RNA (16S rRNA) gene-based studies have reported that lower gut bacterial diversity and the relative abundance of certain bacteria after aHSCT are associated with aGVHD. Using shotgun metagenomic sequencing and a large cohort, we aimed to confirm and extend these observations. Adult aHSCT recipients with stool samples collected from day -30 to day 100 relative to aHSCT were included. One sample was selected per patient per period (pre-aHSCT (day -30 to day 0), early post-aHSCT (day 1 to day 28), and late post-aHSCT (day 29 to day 100)), resulting in 150 aHSCT recipients and 259 samples. Microbial and clinical factors were tested for differences between time periods and an association with subsequent aGVHD. Patients showed a decline in gut bacterial diversity posttransplant, with several patients developing a dominance of Enterococcus. A total of 36 recipients developed aGVHD at a median of 34 days (interquartile range, 26-50 days) post-aHSCT. Lower microbial gene richness (P = .02), a lower abundance of the genus Blautia (P = .05), and a lower abundance of Akkermansia muciniphila (P = .01) early post-aHSCT was observed in those who developed aGVHD. Myeloablative conditioning was associated with aGVHD along with a reduction in gene richness and abundance of Blautia and A muciniphila. These results confirm low diversity and Blautia being associated with aGVHD. Crucially, we add that pretransplant conditioning is associated with changes in gut microbiota. Investigations are warranted to determine the interplay of gut microbiota and conditioning in the development of aGVHD.

RevDate: 2020-11-24

Noor SO, Al-Zahrani DA, Hussein RM, et al (2020)

Assessment of fungal diversity in soil rhizosphere associated with Rhazya stricta and some desert plants using metagenomics.

Archives of microbiology pii:10.1007/s00203-020-02119-z [Epub ahead of print].

This study aimed to compare the fungal rhizosphere communities of Rhazya stricta, Enneapogon desvauxii, Citrullus colocynthis, Senna italica, and Zygophyllum simplex, and the gut mycobiota of Poekilocerus bufonius (Orthoptera, Pyrgomorphidae, "Usherhopper"). A total of 164,485 fungal reads were observed from the five plant rhizospheres and Usherhopper gut. The highest reads were in S. italica rhizosphere (29,883 reads). Species richness in the P. bufonius gut was the highest among the six samples. Ascomycota was dominant in all samples, with the highest reads in E. desvauxii (26,734 reads) rhizosphere. Sordariomycetes and Dothideomycetes were the dominant classes detected with the highest abundance in C. colocynthis and E. desvauxii rhizospheres. Aspergillus and Ceratobasidium were the most abundant genera in the R. stricta rhizosphere, Fusarium and Penicillium in the E. desvauxii rhizosphere and P. bufonius gut, Ceratobasidium and Myrothecium in the C. colocynthis rhizosphere, Aspergillus and Fusarium in the S. italica rhizosphere, and Cochliobolus in the Z. simplex rhizosphere. Aspergillus terreus was the most abundant species in the R. stricta and S. italica rhizospheres, Fusarium sp. in E. desvauxii rhizosphere, Ceratobasidium sp. in C. colocynthis rhizosphere, Cochliobolus sp. in Z. simplex rhizosphere, and Penicillium sp. in P. bufonius gut. The phylogenetic results revealed the unclassified species were related closely to Ascomycota and the species in E. desvauxii, S. italica and Z. simplex rhizospheres were closely related, where the species in the P. bufonius gut, were closely related to the species in the R. stricta, and C. colocynthis rhizospheres.

RevDate: 2020-11-24

Chen J, Zhao Y, Shang Y, et al (2020)

The clinical significance of simultaneous detection of pathogens from bronchoalveolar lavage fluid and blood samples by metagenomic next-generation sequencing in patients with severe pneumonia.

Journal of medical microbiology [Epub ahead of print].

Introduction. Bloodstream infection is a common complication in patients with severe pneumonia and is regarded as an independent risk factor for prediction of poor outcome. Metagenomic next-generation sequencing (mNGS) has been widely applied for pathogen determination of various clinical specimens from patients with infectious diseases. However, the clinical significance of and necessity for simultaneous pathogen detection of both blood samples and bronchoalveolar lavage fluid (BALF) by mNGS in patients with severe pneumonia remains unclear.Hypothesis/Gap Statement. Simultaneous detection of pathogens from both BALF and blood samples in patients with severe pneumonia helps to determine the complication of the bloodstream infection.Aims. This study aimed to elucidate the clinical significance and necessity of pathogen detection simultaneously in both blood samples and BALF samples with the application of mNGS in patients with severe pneumonia.Methods. In this study, 20 patients with severe pneumonia were enrolled and the potential pathogens in both BALF and blood samples were detected simultaneously by conventional microbial examination and mNGS tests. Moreover, multiple consecutive microbial detections were undertaken to investigate the dynamic variation of pathogens during the course of disease progression in two of the 20 patients.Results. In 85 % (17/20) of the patients with severe pneumonia, various pathogens were determined positively in the BALF by mNGS, including 10 cases with bacterial infection, five cases with viral infection and two cases with fungal infection. By contrast, pathogens in 50 % (10/20) of cases could be detected positively in the BALF by conventional microbial tests. Among 17 severe pneumonia patients with mNGS-positive BALF, pathogens were also identified in 10 cases with mNGS-positive blood samples. By contrast, only one patient complicated with a bloodstream infection could be found by conventional bacterial culture. Moreover, the pathogens from BALF were highly consistent with that from blood samples detected by mNGS in the early stage of the disease. With disease progression and after recurrent antibiotic treatment, significant dynamic changes of the microbial species from the BALF and blood samples could be clearly found by mNGS.Conclusions. This study emphasizes the utility of mNGS in the rapid simultaneous detection of pathogens from both BALF and blood samples in patients with severe pneumonia, and could allow determination of bloodstream infection and guide clinicians regarding antimicrobial treatments.

RevDate: 2020-11-24

Bunterngsook B, Mhuantong W, Kanokratana P, et al (2020)

Identification and characterization of a novel AA9-type lytic polysaccharide monooxygenase from a bagasse metagenome.

Applied microbiology and biotechnology pii:10.1007/s00253-020-11002-2 [Epub ahead of print].

Lytic polysaccharide monooxygenases (LPMOs) are auxiliary enzymes catalyzing oxidative cleavages of cellulose chains in crystalline regions, resulting in their increasing accessibility to the hydrolytic enzyme counterparts and hence higher released sugars from biomass saccharification. In this study, a novel auxiliary protein family 9 LPMO (BgAA9) was identified from a metagenomic library derived from a thermophilic microbial community in bagasse collection site where diverse AA9 and AA10 putative sequences were annotated. The enzyme showed highest similarity to a glycoside hydrolase family 61 from Chaetomium thermophilum. Recombinant BgAA9 expressed in Pichia pastoris cleaved cellohexaose (DP6) into shorter cellooligosaccharides (DP2, DP3, and DP4). Supplementation BgAA9 to a commercial cellulase, Accellerase® 1500 showed strong synergistic effect on saccharification of Avicel® PH101, decrystallized cellulose, filter paper, and alkaline-pretreated sugarcane bagasse, resulting in 63-93% increase in the total reducing sugar yield after incubation at 50 °C for 72 h. Strong synergism was shown between BgAA9 and the cellulase with the highest total fermentable sugar yield obtained from 75:25% of Accellerase®1500:BgAA9 which released 39 mg glucose/FPU (filter paper unit) equivalent to 38.7% higher than Accellerase®1500 alone at the same total protein dosage of 5 mg/g substrate according to the mixture design study. The enzyme represented the first characterized LPMO from environmental metagenome and a potent auxiliary component for biomass saccharification. KEY POINTS: • BgAA9 represents the first characterized LPMO from metagenome. • 12 AA families were annotated in thermophilic bagasse fosmid library by NGS. • BgAA9 showed homology to Cel61 in Chaetomium thermophilum. • BgAA9 oxidized cellohexaose and PASC to DP2, DP4, and DP6. • BgAA9 showed strong synergism to Accellerase on bagasse hydrolysis.

RevDate: 2020-11-24

Graham ED, BJ Tully (2020)

Marine Dadabacteria exhibit genome streamlining and phototrophy-driven niche partitioning.

The ISME journal pii:10.1038/s41396-020-00834-5 [Epub ahead of print].

The remineralization of organic material via heterotrophy in the marine environment is performed by a diverse and varied group of microorganisms that can specialize in the type of organic material degraded and the niche they occupy. The marine Dadabacteria are cosmopolitan in the marine environment and belong to a candidate phylum for which there has not been a comprehensive assessment of the available genomic data to date. Here in, we assess the functional potential of the marine pelagic Dadabacteria in comparison to members of the phylum that originate from terrestrial, hydrothermal, and subsurface environments. Our analysis reveals that the marine pelagic Dadabacteria have streamlined genomes, corresponding to smaller genome sizes and lower nitrogen content of their DNA and predicted proteome, relative to their phylogenetic counterparts. Collectively, the Dadabacteria have the potential to degrade microbial dissolved organic matter, specifically peptidoglycan and phospholipids. The marine Dadabacteria belong to two clades with apparent distinct ecological niches in global metagenomic data: a clade with the potential for photoheterotrophy through the use of proteorhodopsin, present predominantly in surface waters up to 100 m depth; and a clade lacking the potential for photoheterotrophy that is more abundant in the deep photic zone.

RevDate: 2020-11-24

Wang Y, Zhu S, Liu T, et al (2020)

Identification of the rhizospheric microbe and metabolites that led by the continuous cropping of ramie (Boehmeria nivea L. Gaud).

Scientific reports, 10(1):20408 pii:10.1038/s41598-020-77475-3.

Continuous cropping lowers the production and quality of ramie (Boehmeria nivea L. Gaud). This study aimed to reveal the metagenomic and metabolomic changes between the healthy- and obstacle-plant after a long period of continuous cropping. After 10 years of continuous cropping, ramie planted in some portions of the land exhibited weak growth and low yield (Obstacle-group), whereas, ramie planted in the other portion of the land grew healthy (Health-group). We collected rhizosphere soil and root samples from which measurements of soil chemical and plant physiochemical properties were taken. All samples were subjected to non-targeted gas chromatograph-mass spectrometer (GS/MS) metabolome analysis. Further, metagenomics was performed to analyze the functional genes in rhizospheric soil organisms. Based on the findings, ramie in Obstacle-group were characterized by shorter plant height, smaller stem diameter, and lower fiber production than that in Health-group. Besides, the Obstacle-group showed a lower relative abundance of Rhizobiaceae, Lysobacter antibioticus, and Bradyrhizobium japonicum, but a higher relative abundance of Azospirillum lipoferum and A. brasilense compared to the Health-group. Metabolomic analysis results implicated cysteinylglycine (Cys-Gly), uracil, malonate, and glycerol as the key differential metabolites between the Health- and Obstacle-group. Notably, this work revealed that bacteria such as Rhizobia potentially synthesize IAA and are likely to reduce the biotic stress of ramie. L. antibioticus also exerts a positive effect on plants in the fight against biotic stress and is mediated by metabolites including orthophosphate, uracil, and Cys-Gly, which may serve as markers for disease risk. These bacterial effects can play a key role in plant resistance to biotic stress via metabolic and methionine metabolism pathways.

RevDate: 2020-11-24

Gao ZW, L Wang (2020)

[Progress in elucidating the origin of eukaryotes].

Yi chuan = Hereditas, 42(10):929-948.

Knowledge of the origin of eukaryotes is key to broadening our understanding of the eukaryotic genome and the relationship among internal structures within a eukaryotic cell. Since the discovery of archaea in 1977 and the proposal of three-domain tree of life by the American microbiologist Carl Woese, the intimate relationship in evolution between eukaryotes and archaea has been demonstrated by considerable experiments and analyses. From the beginning of the 21st century, with the development of phylogenetic methods and the discovery of new archaeal phyla more related to eukaryotes, increasing evidence has shown that Eukarya and Archaea should be merged into one domain, leading to a two-domain tree of life. Nowadays, the Asgard superphylum discovered via metagenomic analysis is regarded as the closest prokaryotes to eukaryotes. Nevertheless, several key questions are still under debate, such as what the ancestors of the eukaryotes were and when mitochondria emerged. Here, we review the current research progress regarding the changes of the tree of life and the detailed eukaryotic evolutionary mechanism. We show that the recent findings have greatly improved our knowledge on the origin of eukaryotes, which will pave the way for future studies.

RevDate: 2020-11-24

Qian Y, Xu M, Deng T, et al (2020)

Synergistic interactions of Desulfovibrio and Petrimonas for sulfate-reduction coupling polycyclic aromatic hydrocarbon degradation.

Journal of hazardous materials pii:S0304-3894(20)32375-X [Epub ahead of print].

Microbial sulfate-reduction coupling polycyclic aromatic hydrocarbon (PAH) degradation is an important process for the remediation of contaminated sediments. However, little is known about core players and their mechanisms in this process due to the complexity of PAH degradation and the large number of microorganisms involved. Here we analyzed potential core players in a black-odorous sediment using gradient-dilution culturing, isolation and genomic/metagenomic approaches. Along the dilution gradient, microbial PAH degradation and sulfate consumption were not decreased, and even a significant (p = 0.003) increase was observed in the degradation of phenanthrene although the microbial diversity declined. Two species, affiliated with Desulfovibrio and Petrimonas, were commonly present in all of the gradients as keystone taxa and showed as the dominant microorganisms in the single colony (SB8) isolated from the highest dilution culture with 93.49% and 4.73% of the microbial community, respectively. Desulfovibrio sp. SB8 and Petrimonas sp. SB8 could serve together as core players for sulfate-reduction coupling PAH degradation, in which Desulfovibrio sp. SB8 could degrade PAHs to hexahydro-2-naphthoyl through the carboxylation pathway while Petrimonas sp. SB8 might degrade intermediate metabolites of PAHs. This study provides new insights into the microbial sulfate-reduction coupling PAH degradation in black-odorous sediments.

RevDate: 2020-11-24

Tang X, Shen M, Zhang Y, et al (2020)

The changes in antibiotic resistance genes during 86 years of the soil ripening process without anthropogenic activities.

Chemosphere pii:S0045-6535(20)33182-9 [Epub ahead of print].

This study aimed to reveal the baseline of natural variations in antibiotic resistance genes (ARGs) in soil without anthropogenic activities over the decades. Nine soil samples with different time of soil formation were taken from the Yancheng Wetland National Nature Reserve, China. ARGs and mobile genetic elements (MGEs) were characterized using metagenomic analysis. A total of 196 and 192 subtypes of ARGs were detected in bulk soil and rhizosphere, respectively. The diversity and abundance of ARGs were stable during 69 years probably due to the alkaline pH soil environment but not due to antibiotics. Increases in ARGs after 86 years were probably attributed to more migrant birds inhabited compared with other sampling sites. Multidrug was the most abundant type, and largely shared by soil samples. It was further shown that soil samples could not be clearly distinguished, suggesting a slow process of succession of ARGs in the mudflat. The variation partitioning analysis revealed that the ARG profile was driven by the comprehensive effects exhibited by the bacterial community, MGEs, and environmental factors. Besides, pathogenic bacteria containing ARGs mediated by migrant birds in the area with 86 years of soil formation history nearing human settlements needed special attention. This study revealed the slow variations in ARGs in the soil ripening process without anthropogenic activities over decades, and it provided information for assessing the effect of human activities on the occurrence and dissemination of ARGs.

RevDate: 2020-11-24

Piazzon MC, Naya-Català F, Perera E, et al (2020)

Genetic selection for growth drives differences in intestinal microbiota composition and parasite disease resistance in gilthead sea bream.

Microbiome, 8(1):168 pii:10.1186/s40168-020-00922-w.

BACKGROUND: The key effects of intestinal microbiota in animal health have led to an increasing interest in manipulating these bacterial populations to improve animal welfare. The aquaculture sector is no exception and in the last years, many studies have described these populations in different fish species. However, this is not an easy task, as intestinal microbiota is composed of very dynamic populations that are influenced by different factors, such as diet, environment, host age, and genetics. In the current study, we aimed to determine whether the genetic background of gilthead sea bream (Sparus aurata) influences the intestinal microbial composition, how these bacterial populations are modulated by dietary changes, and the effect of selection by growth on intestinal disease resistance. To that aim, three different groups of five families of gilthead sea bream that were selected during two generations for fast, intermediate, or slow growth (F3 generation) were kept together in the same open-flow tanks and fed a control or a well-balanced plant-based diet during 9 months. Six animals per family and dietary treatment were sacrificed and the adherent bacteria from the anterior intestinal portion were sequenced. In parallel, fish of the fast- and slow-growth groups were infected with the intestinal parasite Enteromyxum leei and the disease signs, prevalence, intensity, and parasite abundance were evaluated.

RESULTS: No differences were detected in alpha diversity indexes among families, and the core bacterial architecture was the prototypical composition of gilthead sea bream intestinal microbiota, indicating no dysbiosis in any of the groups. The plant-based diet significantly changed the microbiota in the intermediate- and slow-growth families, with a much lower effect on the fast-growth group. Interestingly, the smaller changes detected in the fast-growth families potentially accounted for more changes at the metabolic level when compared with the other families. Upon parasitic infection, the fast-growth group showed significantly lower disease signs and parasite intensity and abundance than the slow-growth animals.

CONCLUSIONS: These results show a clear genome-metagenome interaction indicating that the fast-growth families harbor a microbiota that is more flexible upon dietary changes. These animals also showed a better ability to cope with intestinal infections. Video Abstract.

RevDate: 2020-11-24

Liu C, Ponsero AJ, Armstrong DG, et al (2020)

The dynamic wound microbiome.

BMC medicine, 18(1):358 pii:10.1186/s12916-020-01820-6.

BACKGROUND: Diabetic foot ulcers (DFUs) account for the majority of all limb amputations and hospitalizations due to diabetes complications. With 30 million cases of diabetes in the USA and 500,000 new diagnoses each year, DFUs are a growing health problem. Diabetes patients with limb amputations have high postoperative mortality, a high rate of secondary amputation, prolonged inpatient hospital stays, and a high incidence of re-hospitalization. DFU-associated amputations constitute a significant burden on healthcare resources that cost more than 10 billion dollars per year. Currently, there is no way to identify wounds that will heal versus those that will become severely infected and require amputation.

MAIN BODY: Accurate identification of causative pathogens in diabetic foot ulcers is a critical component of effective treatment. Compared to traditional culture-based methods, advanced sequencing technologies provide more comprehensive and unbiased profiling on wound microbiome with a higher taxonomic resolution, as well as functional annotation such as virulence and antibiotic resistance. In this review, we summarize the latest developments in defining the microbiology of diabetic foot ulcers that have been unveiled by sequencing technologies and discuss both the future promises and current limitations of these approaches. In particular, we highlight the temporal patterns and system dynamics in the diabetic foot microbiome monitored and measured during wound progression and medical intervention, and explore the feasibility of molecular diagnostics in clinics.

CONCLUSION: Molecular tests conducted during weekly office visits to clean and examine DFUs would allow clinicians to offer personalized treatment and antibiotic therapy. Personalized wound management could reduce healthcare costs, improve quality of life for patients, and recoup lost productivity that is important not only to the patient, but also to healthcare payers and providers. These efforts could also improve antibiotic stewardship and control the rise of "superbugs" vital to global health.

RevDate: 2020-11-24

Peterson BD, McDaniel EA, Schmidt AG, et al (2020)

Mercury Methylation Genes Identified across Diverse Anaerobic Microbial Guilds in a Eutrophic Sulfate-Enriched Lake.

Environmental science & technology [Epub ahead of print].

Mercury (Hg) methylation is a microbially mediated process that converts inorganic Hg into bioaccumulative, neurotoxic methylmercury (MeHg). The metabolic activity of methylating organisms is highly dependent on biogeochemical conditions, which subsequently influences MeHg production. However, our understanding of the ecophysiology of methylators in natural ecosystems is still limited. Here, we identified potential locations of MeHg production in the anoxic, sulfidic hypolimnion of a freshwater lake. At these sites, we used shotgun metagenomics to characterize microorganisms with the Hg-methylation gene hgcA. Putative methylators were dominated by hgcA sequences divergent from those in well-studied, confirmed methylators. Using genome-resolved metagenomics, we identified organisms with hgcA (hgcA+) within the Bacteroidetes and the recently described Kiritimatiellaeota phyla. We identified hgcA+ genomes derived from sulfate-reducing bacteria, but these accounted for only 22% of hgcA+ genome coverage. The most abundant hgcA+ genomes were from fermenters, accounting for over half of the hgcA gene coverage. Many of these organisms also mediate hydrolysis of polysaccharides, likely from cyanobacterial blooms. This work highlights the distribution of the Hg-methylation genes across microbial metabolic guilds and indicate that primary degradation of polysaccharides and fermentation may play an important but unrecognized role in MeHg production in the anoxic hypolimnion of freshwater lakes.

RevDate: 2020-11-24

Hoon-Hanks LL, Stöhr AC, Anderson AJ, et al (2020)

Serpentovirus (Nidovirus) and Orthoreovirus Coinfection in Captive Veiled Chameleons (Chamaeleo calyptratus) with Respiratory Disease.

Viruses, 12(11): pii:v12111329.

Serpentoviruses are an emerging group of nidoviruses known to cause respiratory disease in snakes and have been associated with disease in other non-avian reptile species (lizards and turtles). This study describes multiple episodes of respiratory disease-associated mortalities in a collection of juvenile veiled chameleons (Chamaeleo calyptratus). Histopathologic lesions included rhinitis and interstitial pneumonia with epithelial proliferation and abundant mucus. Metagenomic sequencing detected coinfection with two novel serpentoviruses and a novel orthoreovirus. Veiled chameleon serpentoviruses are most closely related to serpentoviruses identified in snakes, lizards, and turtles (approximately 40-50% nucleotide and amino acid identity of ORF1b). Veiled chameleon orthoreovirus is most closely related to reptilian orthoreoviruses identified in snakes (approximately 80-90% nucleotide and amino acid identity of the RNA-dependent RNA polymerase). A high prevalence of serpentovirus infection (>80%) was found in clinically healthy subadult and adult veiled chameleons, suggesting the potential for chronic subclinical carriers. Juvenile veiled chameleons typically exhibited a more rapid progression compared to subadults and adults, indicating a possible age association with morbidity and mortality. This is the first description of a serpentovirus infection in any chameleon species. A causal relationship between serpentovirus infection and respiratory disease in chameleons is suspected. The significance of orthoreovirus coinfection remains unknown.

RevDate: 2020-11-24

Vernocchi P, Gili T, Conte F, et al (2020)

Network Analysis of Gut Microbiome and Metabolome to Discover Microbiota-Linked Biomarkers in Patients Affected by Non-Small Cell Lung Cancer.

International journal of molecular sciences, 21(22): pii:ijms21228730.

Several studies in recent times have linked gut microbiome (GM) diversity to the pathogenesis of cancer and its role in disease progression through immune response, inflammation and metabolism modulation. This study focused on the use of network analysis and weighted gene co-expression network analysis (WGCNA) to identify the biological interaction between the gut ecosystem and its metabolites that could impact the immunotherapy response in non-small cell lung cancer (NSCLC) patients undergoing second-line treatment with anti-PD1. Metabolomic data were merged with operational taxonomic units (OTUs) from 16S RNA-targeted metagenomics and classified by chemometric models. The traits considered for the analyses were: (i) condition: disease or control (CTRLs), and (ii) treatment: responder (R) or non-responder (NR). Network analysis indicated that indole and its derivatives, aldehydes and alcohols could play a signaling role in GM functionality. WGCNA generated, instead, strong correlations between short-chain fatty acids (SCFAs) and a healthy GM. Furthermore, commensal bacteria such as Akkermansia muciniphila, Rikenellaceae, Bacteroides, Peptostreptococcaceae, Mogibacteriaceae and Clostridiaceae were found to be more abundant in CTRLs than in NSCLC patients. Our preliminary study demonstrates that the discovery of microbiota-linked biomarkers could provide an indication on the road towards personalized management of NSCLC patients.

RevDate: 2020-11-24
CmpDate: 2020-11-24

Doan T, Worden L, Hinterwirth A, et al (2020)

Macrolide and Nonmacrolide Resistance with Mass Azithromycin Distribution.

The New England journal of medicine, 383(20):1941-1950.

BACKGROUND: Mass distribution of azithromycin to preschool children twice yearly for 2 years has been shown to reduce childhood mortality in sub-Saharan Africa but at the cost of amplifying macrolide resistance. The effects on the gut resistome, a reservoir of antimicrobial resistance genes in the body, of twice-yearly administration of azithromycin for a longer period are unclear.

METHODS: We investigated the gut resistome of children after they received twice-yearly distributions of azithromycin for 4 years. In the Niger site of the MORDOR trial, we enrolled 30 villages in a concurrent trial in which they were randomly assigned to receive mass distribution of either azithromycin or placebo, offered to all children 1 to 59 months of age every 6 months for 4 years. Rectal swabs were collected at baseline, 36 months, and 48 months for analysis of the participants' gut resistome. The primary outcome was the ratio of macrolide-resistance determinants in the azithromycin group to those in the placebo group at 48 months.

RESULTS: Over the entire 48-month period, the mean (±SD) coverage was 86.6±12% in the villages that received placebo and 83.2±16.4% in the villages that received azithromycin. A total of 3232 samples were collected during the entire trial period; of the samples obtained at the 48-month monitoring visit, 546 samples from 15 villages that received placebo and 504 from 14 villages that received azithromycin were analyzed. Determinants of macrolide resistance were higher in the azithromycin group than in the placebo group: 7.4 times as high (95% confidence interval [CI], 4.0 to 16.7) at 36 months and 7.5 times as high (95% CI, 3.8 to 23.1) at 48 months. Continued mass azithromycin distributions also selected for determinants of nonmacrolide resistance, including resistance to beta-lactam antibiotics, an antibiotic class prescribed frequently in this region of Africa.

CONCLUSIONS: Among villages assigned to receive mass distributions of azithromycin or placebo twice yearly for 4 years, antibiotic resistance was more common in the villages that received azithromycin than in those that received placebo. This trial showed that mass azithromycin distributions may propagate antibiotic resistance. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT02047981.).

RevDate: 2020-11-24
CmpDate: 2020-11-24

Ozga AT, Gilby I, Nockerts RS, et al (2019)

Oral microbiome diversity in chimpanzees from Gombe National Park.

Scientific reports, 9(1):17354 pii:10.1038/s41598-019-53802-1.

Historic calcified dental plaque (dental calculus) can provide a unique perspective into the health status of past human populations but currently no studies have focused on the oral microbial ecosystem of other primates, including our closest relatives, within the hominids. Here we use ancient DNA extraction methods, shotgun library preparation, and next generation Illumina sequencing to examine oral microbiota from 19 dental calculus samples recovered from wild chimpanzees (Pan troglodytes schweinfurthii) who died in Gombe National Park, Tanzania. The resulting sequences were trimmed for quality, analyzed using MALT, MEGAN, and alignment scripts, and integrated with previously published dental calculus microbiome data. We report significant differences in oral microbiome phyla between chimpanzees and anatomically modern humans (AMH), with chimpanzees possessing a greater abundance of Bacteroidetes and Fusobacteria, and AMH showing higher Firmicutes and Proteobacteria. Our results suggest that by using an enterotype clustering method, results cluster largely based on host species. These clusters are driven by Porphyromonas and Fusobacterium genera in chimpanzees and Haemophilus and Streptococcus in AMH. Additionally, we compare a nearly complete Porphyromonas gingivalis genome to previously published genomes recovered from human gingiva to gain perspective on evolutionary relationships across host species. Finally, using shotgun sequence data we assessed indicators of diet from DNA in calculus and suggest exercising caution when making assertions related to host lifestyle. These results showcase core differences between host species and stress the importance of continued sequencing of nonhuman primate microbiomes in order to fully understand the complexity of their oral ecologies.

RevDate: 2020-11-23

Sun W, Lu Z, L Yan (2020)

Clinical Efficacy of Metagenomic Next-Generation Sequencing (mNGS) For Rapid detection of Mycobacterium Tuberculosis in Smear-Negative Extrapulmonary Specimens in a high TB burden area.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(20)32477-2 [Epub ahead of print].

OBJECTIVE: To assess the clinical utility of mNGS in smear-negative extrapulmonary specimens collected from China.

METHODS: Specimens were tested by mNGS and other routine TB tests. The diagnostic accuracy of mNGS was calculated and compared with the final clinical diagnosis.

RESULTS: The sensitivity of mNGS is significantly higher than that of other routine TB tests. ROC curves showed mNGS achieved the highest areas under curve (AUC) value of 0.79. The mNGS positive rate of tuberculous meningitis was the highest. All non-tuberculous extrapulmonary pathogens were directly and simultaneously detected.

CONCLUSION: The mNGS seemed to be superior to all previous TB etiological tests in smear-negative extrapulmonary specimens and could identify all possible pathogens at once within 48 h.

RevDate: 2020-11-23

Geng S, Mei Q, Zhu C, et al (2020)

Metagenomic next-generation sequencing technology for detection of pathogens in blood of critically ill patients.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(20)32478-4 [Epub ahead of print].

OBJECTIVE: To explore the applicability of metagenomic next-generation sequencing (mNGS) technology for the detection of blood pathogens in intensive care unit patients.

METHODS: The clinical data of 63 critically ill patients who could not be diagnosed with blood culture (BC) and who underwent mNGS blood sample testing were retrospectively analyzed. The diagnostic efficacy of mNGS was compared with that of traditional detection methods; the distribution of the pathogens identified by mNGS was analyzed; and the differences in laboratory tests, comorbidities, treatment, and prognosis between the mNGS-positive and mNGS-negative groups were compared.

RESULTS: The positive rate of mNGS was 41.3% (26/63), and 16 patients were found to have mixed infections. However, the positive rate of BCs performed simultaneously with mNGS was only 7.9% (5/63). The results of univariate analysis showed that the average length of intensive care unit stay (β, -8.689 [95% CI, -16.176, -1.202]; P = 0.026) and the time from onset to sequencing (β, -5.816 [95% CI,-9.936, -1.696]; P = 0.007) of the mNGS-positive group were significantly shorter than those of the mNGS-negative group. More patients in the positive group were adjusted for anti-infective treatment after mNGS (OR, 3.789 [95% CI,1.176, 12.211]; P < 0.001).

CONCLUSIONS: Detection of blood pathogens by mNGS has good applicability for critically ill patients who cannot be diagnosed by BC in the early stages of infection, and mNGS should be performed as early as possible to obtain higher pathogen detection rates.

RevDate: 2020-11-23

Diaz PI (2020)

Subgingival fungi, Archaea, and viruses under the omics loupe.

Periodontology 2000 [Epub ahead of print].

The microbial communities that inhabit the gingival crevice are responsible for the pathological processes that affect the periodontium. The changes in composition and function of subgingival bacteria as disease develops have been extensively studied. Subgingival communities, however, also contain fungi, Archaea, and viruses, which could contribute to the dysbiotic processes associated with periodontal diseases. High-throughput DNA sequencing has facilitated a better understanding of the mycobiome, archaeome, and virome. However, the number of studies available on the nonbacterial components of the subgingival microbiome remains limited in comparison with publications focusing on bacteria. Difficulties in characterizing fungal, archaeal, and viral populations arise from the small portion of the total metagenome mass they occupy and lack of comprehensive reference genome databases. In addition, specialized approaches potentially introducing bias are required to enrich for viral particles, while harsh methods of cell lysis are needed to recover nuclei acids from certain fungi. While the characterization of the subgingival diversity of fungi, Archaea and viruses is incomplete, emerging evidence suggests that they could contribute in different ways to subgingival dysbiosis. Certain fungi, such as Candida albicans are suggested to facilitate colonization of bacterial pathogens. Methanogenic Archaea are associated with periodontitis severity and are thought to partner synergistically with bacterial fermenters, while viruses may affect immune responses or shape microbial communities in ways incompletely understood. This review describes the manner in which omics approaches have improved our understanding of the diversity of fungi, Archaea, and viruses within subgingival communities. Further characterization of these understudied components of the subgingival microbiome is required, together with mechanistic studies to unravel their ecological role and potential contributions to dysbiosis.

RevDate: 2020-11-23

Kumar PS, Dabdoub SM, SM Ganesan (2020)

Probing periodontal microbial dark matter using metataxonomics and metagenomics.

Periodontology 2000 [Epub ahead of print].

Our view of the periodontal microbial community has been shaped by a century or more of cultivation-based and microscopic investigations. While these studies firmly established the infection-mediated etiology of periodontal diseases, it was apparent from the very early days that periodontal microbiology suffered from what Staley and Konopka described as the "great plate count anomaly", in that these culturable bacteria were only a minor part of what was visible under the microscope. For nearly a century, much effort has been devoted to finding the right tools to investigate this uncultivated majority, also known as "microbial dark matter". The discovery that DNA was an effective tool to "see" microbial dark matter was a significant breakthrough in environmental microbiology, and oral microbiologists were among the earliest to capitalize on these advances. By identifying the order in which nucleotides are arranged in a stretch of DNA (DNA sequencing) and creating a repository of these sequences, sequence databases were created. Computational tools that used probability-driven analysis of these sequences enabled the discovery of new and unsuspected species and ascribed novel functions to these species. This review will trace the development of DNA sequencing as a quantitative, open-ended, comprehensive approach to characterize microbial communities in their native environments, and explore how this technology has shifted traditional dogmas on how the oral microbiome promotes health and its role in disease causation and perpetuation.

RevDate: 2020-11-23

Teles F, Wang Y, Hajishengallis G, et al (2020)

Impact of systemic factors in shaping the periodontal microbiome.

Periodontology 2000 [Epub ahead of print].

Since 2010, next-generation sequencing platforms have laid the foundation to an exciting phase of discovery in oral microbiology as it relates to oral and systemic health and disease. Next-generation sequencing has allowed large-scale oral microbial surveys, based on informative marker genes, such as 16S ribosomal RNA, community gene inventories (metagenomics), and functional analyses (metatranscriptomics), to be undertaken. More specifically, the availability of next-generation sequencing has also paved the way for studying, in greater depth and breadth, the effect of systemic factors on the periodontal microbiome. It was natural to investigate systemic diseases, such as diabetes, in such studies, along with systemic conditions or states, , pregnancy, menopause, stress, rheumatoid arthritis, and systemic lupus erythematosus. In addition, in recent years, the relevance of systemic "variables" (ie, factors that are not necessarily diseases or conditions, but may modulate the periodontal microbiome) has been explored in detail. These include ethnicity and genetics. In the present manuscript, we describe and elaborate on the new and confirmatory findings unveiled by next-generation sequencing as it pertains to systemic factors that may shape the periodontal microbiome. We also explore the systemic and mechanistic basis for such modulation and highlight the importance of those relationships in the management and treatment of patients.

RevDate: 2020-11-23

Duran-Pinedo AE (2020)

Metatranscriptomic analyses of the oral microbiome.

Periodontology 2000 [Epub ahead of print].

Although the composition of the oral human microbiome is now well studied, regulation of genes within oral microbial communities remains mostly uncharacterized. Current concepts of periodontal disease and caries highlight the importance of oral biofilms and their role as etiological agents of those diseases. Currently, there is increased interest in exploring and characterizing changes in the composition and gene-expression profiles of oral microbial communities. These efforts aim to identify changes in functional activities that could explain the transition from health to disease and the reason for the chronicity of those infections. It is now clear that the functions of distinct species within the subgingival microbiota are intimately intertwined with the rest of the microbial community. This point highlights the relevance of examining the expression profile of specific species within the subgingival microbiota in the case of periodontal disease or caries lesions, in the context of the other members of the biofilm in vivo. Metatranscriptomic analysis of the oral community is the starting point for identifying environmental signals that modulate the shift in metabolism of the community from commensal to dysbiotic. These studies give a snapshot of the expression patterns of microbial communities and also allow us to determine triggers to diseases. For example, in the case of caries, studies have unveiled a potential new pathway of sugar metabolism, namely the use of sorbitol as an additional source of carbon by Streptococcus mutans; and in the case of periodontal disease, high levels of extracellular potassium could be a signal of disease. Longitudinal studies are needed to identify the real markers of the initial stages of caries and periodontal disease. More information on the gene-expression profiles of the host, along with the patterns from the microbiome, will lead to a clearer understanding of the modulation of health and disease. This review presents a summary of these initial studies, which have opened the door to a new understanding of the dynamics of the oral community during the dysbiotic process in the oral cavity.

RevDate: 2020-11-23

Shokeen B, Dinis MDB, Haghighi F, et al (2020)

Omics and interspecies interaction.

Periodontology 2000 [Epub ahead of print].

Interspecies interactions are key determinants in biofilm behavior, ecology, and architecture. The cellular responses of microorganisms to each other at transcriptional, proteomic, and metabolomic levels ultimately determine the characteristics of biofilm and the corresponding implications for health and disease. Advances in omics technologies have revolutionized our understanding of microbial community composition and their activities as a whole. Large-scale analyses of the complex interaction between the many microbial species residing within a biofilm, however, are currently still hampered by technical and bioinformatics challenges. Thus, studies of interspecies interactions have largely focused on the transcriptional and proteomic changes that occur during the contact of a few prominent species, such as Porphyromonas gingivalis, Streptococcus mutans, Candida albicans, and a few others, with selected partner species. Expansion of available tools is necessary to grow the revealing, albeit limited, insight these studies have provided into a profound understanding of the nature of individual microbial responses to the presence of others. This will allow us to answer important questions including: Which intermicrobial interactions orchestrate the myriad of cooperative, synergistic, antagonistic, manipulative, and other types of relationships and activities in the complex biofilm environment, and what are the implications for oral health and disease?

RevDate: 2020-11-23

Kumar PS (2020)

Microbiomics: Were we all wrong before?.

Periodontology 2000 [Epub ahead of print].

Periodontal microbiology has historically been based on an "us against them" paradigm, one that focuses mainly on identifying microbes and viruses that cause disease. However, such a bottom-up approach limits our appreciation of the incredible diversity of this ecosystem and the essential ways in which microbial interactions contribute to health and homeostasis of the subgingival niche. Microbiomics-the science of collectively characterizing and quantifying molecules responsible for the structure, function, and dynamics of a microbial community-has enabled us to study these communities in their natural habitat, thereby revolutionizing our knowledge of host-associated microbes and reconceptualizing our definition of "human." When this systems-biology approach is combined with ecologic principles, it explicates the complex relationship that exist between microbiota and between them and us, the human. In this volume of Periodontology 2000, a group of 12 female scientists take the lead in investigating how metagenomics, genomics, metatranscriptomics, proteomics, metaproteomics, and metabolomics have achieved the following: (a) widened our view of the periodontal microbiome; (b) expanded our understanding of the evolution of the human oral microbiome; (c) shone a light on not just bacteria, but also other prokaryotic and eukaryotic members of the community; (d) elucidated the effects of anthropogenic behavior and systemic diseases on shaping these communities; and (e) influenced traditional patterns of periodontal therapeutics.

RevDate: 2020-11-23

Huang L, Xu C, Yang W, et al (2020)

A machine learning framework to determine geolocations from metagenomic profiling.

Biology direct, 15(1):27 pii:10.1186/s13062-020-00278-z.

BACKGROUND: Studies on metagenomic data of environmental microbial samples found that microbial communities seem to be geolocation-specific, and the microbiome abundance profile can be a differentiating feature to identify samples' geolocations. In this paper, we present a machine learning framework to determine the geolocations from metagenomics profiling of microbial samples.

RESULTS: Our method was applied to the multi-source microbiome data from MetaSUB (The Metagenomics and Metadesign of Subways and Urban Biomes) International Consortium for the CAMDA 2019 Metagenomic Forensics Challenge (the Challenge). The goal of the Challenge is to predict the geographical origins of mystery samples by constructing microbiome fingerprints.First, we extracted features from metagenomic abundance profiles. We then randomly split the training data into training and validation sets and trained the prediction models on the training set. Prediction performance was evaluated on the validation set. By using logistic regression with L2 normalization, the prediction accuracy of the model reaches 86%, averaged over 100 random splits of training and validation datasets.The testing data consists of samples from cities that do not occur in the training data. To predict the "mystery" cities that are not sampled before for the testing data, we first defined biological coordinates for sampled cities based on the similarity of microbial samples from them. Then we performed affine transform on the map such that the distance between cities measures their biological difference rather than geographical distance. After that, we derived the probabilities of a given testing sample from unsampled cities based on its predicted probabilities on sampled cities using Kriging interpolation. Results show that this method can successfully assign high probabilities to the true cities-of-origin of testing samples.

CONCLUSION: Our framework shows good performance in predicting the geographic origin of metagenomic samples for cities where training data are available. Furthermore, we demonstrate the potential of the proposed method to predict metagenomic samples' geolocations for samples from locations that are not in the training dataset.

RevDate: 2020-11-23

Bollmann-Giolai A, Giolai M, Heavens D, et al (2020)

A low-cost pipeline for soil microbiome profiling.

MicrobiologyOpen [Epub ahead of print].

Common bottlenecks in environmental and crop microbiome studies are the consumable and personnel costs necessary for genomic DNA extraction and sequencing library construction. This is harder for challenging environmental samples such as soil, which is rich in Polymerase Chain Reaction (PCR) inhibitors. To address this, we have established a low-cost genomic DNA extraction method for soil samples. We also present an Illumina-compatible 16S and ITS rRNA gene amplicon library preparation workflow that uses common laboratory equipment. We evaluated the performance of our genomic DNA extraction method against two leading commercial soil genomic DNA kits (MoBio PowerSoil® and MP Biomedicals™ FastDNA™ SPIN) and a recently published non-commercial extraction method by Zou et al. (PLoS Biology, 15, e2003916, 2017). Our benchmarking experiment used four different soil types (coniferous, broad-leafed, and mixed forest plus a standardized cereal crop compost mix) assessing the quality and quantity of the extracted genomic DNA by analyzing sequence variants of 16S V4 and ITS rRNA amplicons. We found that our genomic DNA extraction method compares well to both commercially available genomic DNA extraction kits in DNA quality and quantity. The MoBio PowerSoil® kit, which relies on silica column-based DNA extraction with extensive washing, delivered the cleanest genomic DNA, for example, best A260:A280 and A260:A230 absorbance ratios. The MP Biomedicals™ FastDNA™ SPIN kit, which uses a large amount of binding material, yielded the most genomic DNA. Our method fits between the two commercial kits, producing both good yields and clean genomic DNA with fragment sizes of approximately 10 kb. Comparative analysis of detected amplicon sequence variants shows that our method correlates well with the two commercial kits. Here, we present a low-cost genomic DNA extraction method for soil samples that can be coupled to an Illumina-compatible simple two-step amplicon library construction workflow for 16S V4 and ITS marker genes. Our method delivers high-quality genomic DNA at a fraction of the cost of commercial kits and enables cost-effective, large-scale amplicon sequencing projects. Notably, our extracted gDNA molecules are long enough to be suitable for downstream techniques such as full gene sequencing or even metagenomics shotgun approaches using long reads (PacBio or Nanopore), 10x Genomics linked reads, and Dovetail genomics.

RevDate: 2020-11-23

Hu Y, Xie H, Gao M, et al (2020)

Dynamic of Composition and Diversity of Gut Microbiota in Triatoma rubrofasciata in Different Developmental Stages and Environmental Conditions.

Frontiers in cellular and infection microbiology, 10:587708.

Triatoma rubrofasciata (T. rubrofasciata), one kind of triatomine insects, is the vector of Trypanosoma cruzi (T. cruzi), which lead to American trypanosomiasis. Although the gut microbiome may play an essential role in the development and susceptibility of triatomine, there is limited research on the gut microbiota of T. rubrofasciata. To elucidate the effect of the vector's developmental stages and environmental conditions on the gut microbiome, we employed 16S rRNA gene sequencing to profile the gut bacterial community diversity and composition of T. rubrofasciata. Significant shifts were observed in the overall gut microbe diversity and composition across the development of T. rubrofasciata and specific bacteria were detected in different stages. Serratia and Burkholderia-Caballeronia-Paraburkholderia were dominant in the 1st nymphal stage, while the abundance of Staphylococcus was low in the 1st nymphal stage. Oceanicaulis were undetectable in the adult stage and Odoribacter peaked in the 2nd nymphal stage. Moreover, Staphylococcus was correlated negatively with Serratia. Likewise, the total gut microbiota diversity and composition of T. rubrofasciata differentiated significantly by environmental conditions. The ingestion of a bloodmeal increased alpha diversity of gut bacterial communities, and Staphylococcus was more abundant in laboratory-reared bugs whereas Enterococcus enriched in wild-caught bugs. Furthermore, Pantoea was negatively correlated with Staphylococcus, and positively related to Bacillus only. The phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) algorithm showed obvious metagenomic functional differences by environmental conditions, and Chagas disease relevant pathway was enriched in wild-caught T. rubrofasciata.

RevDate: 2020-11-23

Feranchuk S, Belkova N, Chernogor L, et al (2018)

The signs of adaptive mutations identified in the chloroplast genome of the algae endosymbiont of Baikal sponge.

F1000Research, 7:1405.

Background: The study of ecosystems of the great lakes is important as observations can be extended to ecosystems of larger scale. The ecological crisis of Lake Baikal needs investigations to discover the molecular mechanisms involved in the crisis. The disease of Baikal sponges is one of the processes resulting in the degradation of the littoral zone of the lake. Methods: The chloroplast genome fragment for the algae endosymbiont of Baikal sponge was assembled from metagenomic sequencing data. The distributions of polymorphic sites were obtained for the genome fragment, separately for samples from healthy sponge, diseased sponge and dead sponge tissues. Results: The comparative analysis of chloroplast genome sequences suggests that the symbiotic algae from Baikal sponge is close to Choricystis genus of unicellular algae. Also, the distributions of polymorphic sites allowed detection of the signs of extensive mutations in the chloroplasts isolated from the diseased sponge tissues. Conclusions: The study demonstrate the particular case of evolution at the molecular level due to the conditions of a severe crisis of a whole ecosystem in Lake Baikal. The detection of adaptive mutations in the chloroplast genome is an important feature which could represent the behavior of an ecosystem in the event of a severe crisis.

RevDate: 2020-11-23

Wang J, Bai X, Peng C, et al (2020)

Fermented milk containing Lactobacillus casei Zhang and Bifidobacterium animalis ssp. lactis V9 alleviated constipation symptoms through regulation of intestinal microbiota, inflammation, and metabolic pathways.

Journal of dairy science, 103(12):11025-11038.

Studies suggest that probiotics and fermented milk can improve defecation in constipated patients. However, the mechanism of fermented milk containing probiotics on constipation remains poorly understood. Volunteers with chronic constipation symptoms were recruited and given 200 g/d of fermented milk containing Lactobacillus casei Zhang and Bifidobacterium animalis ssp. lactis V9 (PFM) for 4 wk. Clinical symptoms, cytokines, metagenomics, and metabolomics were evaluated in constipated participants before and after PFM intervention. After PFM intervention, we observed significant improvement of constipation symptoms. In the serum samples, the anti-inflammatory cytokine IL-10 increased and the proinflammatory cytokine C-reactive protein and lipopolysaccharides decreased. Metagenomics results showed that the increase of B. animalis was correlated with an increase in defecation frequency. Fatty acid biosynthesis and bile acid biosynthesis in stool samples as well as carnitine shuttle, vitamin E metabolism, and ascorbate and aldarate metabolism were identified as significantly altered metabolic pathways. Acylcarnitine, located on the carnitine shuttle pathway, had a significantly positive correlation with defecation frequency. It was speculated that PFM may contribute to alleviating constipation symptoms through 3 potential mechanisms: fine-tuning gastrointestinal microbiota, fighting inflammation, and regulating metabolic pathways.

RevDate: 2020-11-23
CmpDate: 2020-11-23

Berlemont R, Winans N, Talamantes D, et al (2020)

MetaGeneHunt for protein domain annotation in short-read metagenomes.

Scientific reports, 10(1):7712.

The annotation of short-reads metagenomes is an essential process to understand the functional potential of sequenced microbial communities. Annotation techniques based solely on the identification of local matches tend to confound local sequence similarity and overall protein homology and thus don't mirror the complex multidomain architecture and the shuffling of functional domains in many protein families. Here, we present MetaGeneHunt to identify specific protein domains and to normalize the hit-counts based on the domain length. We used MetaGeneHunt to investigate the potential for carbohydrate processing in the mouse gastrointestinal tract. We sampled, sequenced, and analyzed the microbial communities associated with the bolus in the stomach, intestine, cecum, and colon of five captive mice. Focusing on Glycoside Hydrolases (GHs) we found that, across samples, 58.3% of the 4,726,023 short-read sequences matching with a GH domain-containing protein were located outside the domain of interest. Next, before comparing the samples, the counts of localized hits matching the domains of interest were normalized to account for the corresponding domain length. Microbial communities in the intestine and cecum displayed characteristic GH profiles matching distinct microbial assemblages. Conversely, the stomach and colon were associated with structurally and functionally more diverse and variable microbial communities. Across samples, despite fluctuations, changes in the functional potential for carbohydrate processing correlated with changes in community composition. Overall MetaGeneHunt is a new way to quickly and precisely identify discrete protein domains in sequenced metagenomes processed with MG-RAST. In addition, using the sister program "GeneHunt" to create custom Reference Annotation Table, MetaGeneHunt provides an unprecedented way to (re)investigate the precise distribution of any protein domain in short-reads metagenomes.

RevDate: 2020-11-23
CmpDate: 2020-11-23

De Angelis M, Ferrocino I, Calabrese FM, et al (2020)

Diet influences the functions of the human intestinal microbiome.

Scientific reports, 10(1):4247.

Gut microbes programme their metabolism to suit intestinal conditions and convert dietary components into a panel of small molecules that ultimately affect host physiology. To unveil what is behind the effects of key dietary components on microbial functions and the way they modulate host-microbe interaction, we used for the first time a multi-omic approach that goes behind the mere gut phylogenetic composition and provides an overall picture of the functional repertoire in 27 fecal samples from omnivorous, vegan and vegetarian volunteers. Based on our data, vegan and vegetarian diets were associated to the highest abundance of microbial genes/proteins responsible for cell motility, carbohydrate- and protein-hydrolyzing enzymes, transport systems and the synthesis of essential amino acids and vitamins. A positive correlation was observed when intake of fiber and the relative fecal abundance of flagellin were compared. Microbial cells and flagellin extracted from fecal samples of 61 healthy donors modulated the viability of the human (HT29) colon carcinoma cells and the host response through the stimulation of the expression of Toll-like receptor 5, lectin RegIIIα and three interleukins (IL-8, IL-22 and IL-23). Our findings concretize a further and relevant milestone on how the diet may prevent/mitigate disease risk.

RevDate: 2020-11-23
CmpDate: 2020-11-23

Queiroz LL, Bendia AG, Duarte RTD, et al (2020)

Bacterial diversity in deep-sea sediments under influence of asphalt seep at the São Paulo Plateau.

Antonie van Leeuwenhoek, 113(5):707-717.

Here we investigated the diversity of bacterial communities from deep-sea surface sediments under influence of asphalt seeps at the Sao Paulo Plateau using next-generation sequencing method. Sampling was performed at North São Paulo Plateau using the human occupied vehicle Shinkai 6500 and her support vessel Yokosuka. The microbial diversity was studied at two surficial sediment layers (0-1 and 1-4 cm) of five samples collected in cores in water depths ranging from 2456 to 2728 m. Bacterial communities were studied through sequencing of 16S rRNA gene on the Ion Torrent platform and clustered in operational taxonomic units. We observed high diversity of bacterial sediment communities as previously described by other studies. When we considered community composition, the most abundant classes were Alphaproteobacteria (27.7%), Acidimicrobiia (20%), Gammaproteobacteria (11.3%) and Deltaproteobacteria (6.6%). Most abundant OTUs at family level were from two uncultured bacteria from Actinomarinales (5.95%) and Kiloniellaceae (3.17%). The unexpected high abundance of Alphaproteobacteria and Acidimicrobiia in our deep-sea microbial communities may be related to the presence of asphalt seep at North São Paulo Plateau, since these bacterial classes contain bacteria that possess the capability of metabolizing hydrocarbon compounds.

RevDate: 2020-11-22

Kasmanas JC, Bartholomäus A, Corrêa FB, et al (2020)

HumanMetagenomeDB: a public repository of curated and standardized metadata for human metagenomes.

Nucleic acids research pii:5998395 [Epub ahead of print].

Metagenomics became a standard strategy to comprehend the functional potential of microbial communities, including the human microbiome. Currently, the number of metagenomes in public repositories is increasing exponentially. The Sequence Read Archive (SRA) and the MG-RAST are the two main repositories for metagenomic data. These databases allow scientists to reanalyze samples and explore new hypotheses. However, mining samples from them can be a limiting factor, since the metadata available in these repositories is often misannotated, misleading, and decentralized, creating an overly complex environment for sample reanalysis. The main goal of the HumanMetagenomeDB is to simplify the identification and use of public human metagenomes of interest. HumanMetagenomeDB version 1.0 contains metadata of 69 822 metagenomes. We standardized 203 attributes, based on standardized ontologies, describing host characteristics (e.g. sex, age and body mass index), diagnosis information (e.g. cancer, Crohn's disease and Parkinson), location (e.g. country, longitude and latitude), sampling site (e.g. gut, lung and skin) and sequencing attributes (e.g. sequencing platform, average length and sequence quality). Further, HumanMetagenomeDB version 1.0 metagenomes encompass 58 countries, 9 main sample sites (i.e. body parts), 58 diagnoses and multiple ages, ranging from just born to 91 years old. The HumanMetagenomeDB is publicly available at https://webapp.ufz.de/hmgdb/.

RevDate: 2020-11-22

Das N, Kotoky R, Maurya AP, et al (2020)

Paradigm shift in antibiotic-resistome of petroleum hydrocarbon contaminated soil.

The Science of the total environment pii:S0048-9697(20)37308-3 [Epub ahead of print].

The increasing prevalence of antibiotic-resistant microorganisms in both clinical and environmental samples is of great concern for public health. In the present study, environmental samples from seven different sites, heavily contaminated with petroleum hydrocarbons has been examined for the antimicrobial resistome through metagenomic approach. The soil samples were found to be contaminated with high concentration of total petroleum hydrocarbons (average 45 g/kg), polyaromatic hydrocarbons (average ∑16PAH = 280 mg/kg), and heavy metals, which shapes the microbial community and their function. Proteobacteria was found to be predominant phylum in the contaminated habitat with the highest diversity (55.91%) followed by Actinobacteria (9.86%). Although the taxonomical abundance of the non-contaminated sample was not significantly different from contaminated samples, the functional abundance of genes related to antibiotic resistance was found to be higher up to 2 fold in contaminated samples. The comparative metagenomic analysis revealed a higher abundance of different antibiotic resistance genes, especially genes for fluoroquinolones was found to be higher up to 10 fold in contaminated samples. Moreover, the study has shown a significant difference in total functional diversity and abundance, mainly genes for aromatic compound metabolism and genes for phages, mobile genetic elements. These higher abundances of well recognized antibiotic resistance genes, multidrug efflux pumps, and integrons, suggest that the petroleum hydrocarbon contaminated sites can act as reservoirs for development of antibiotic resistance genes (ARGs). From this study, a significant link between the presence of petroleum hydrocarbon and the development of antibiotic resistance in the microbiome of contaminated habitat has been established.

RevDate: 2020-11-21

Nasukawa T, Sugimoto R, Uchiyama J, et al (2020)

Purification of membrane vesicles from Gram-positive bacteria using flow cytometry, after iodixanol density-gradient ultracentrifugation.

Research in microbiology pii:S0923-2508(20)30105-4 [Epub ahead of print].

Membrane vesicles (MVs) play biologically important roles in Gram-positive bacteria, and purification is essential for their study. Although high-performance flow cytometry has the capability to quantify and isolate specific small particles, it has not been examined for MV isolation. In this study, we used high-performance flow cytometry to analyze MV from Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, prepared by iodixanol density-gradient ultracentrifugation. Analysis of the quality of MV samples before and after sorting showed that the flow cytometric sorting provided higher purity and uniformity compared to gradient isolation alone. The MV purification method using flow cytometry should prove useful for applications requiring a very high purity of MV samples such as proteomic, metagenomic or lipidomic studies.

RevDate: 2020-11-21

Antonson AM, Evans MV, Galley JD, et al (2020)

Unique maternal immune and functional microbial profiles during prenatal stress.

Scientific reports, 10(1):20288 pii:10.1038/s41598-020-77265-x.

Maternal stress during pregnancy is widespread and is associated with poor offspring outcomes, including long-term mental health issues. Prenatal stress-induced fetal neuroinflammation is thought to underlie aberrant neurodevelopment and to derive from a disruption in intrauterine immune homeostasis, though the exact origins are incompletely defined. We aimed to identify divergent immune and microbial metagenome profiles of stressed gestating mice that may trigger detrimental inflammatory signaling at the maternal-fetal interface. In response to stress, maternal glucocorticoid circuit activation corresponded with indicators of systemic immunosuppression. At the maternal-fetal interface, density of placental mononuclear leukocytes decreased with stress, yet maternal whole blood leukocyte analysis indicated monocytosis and classical M1 phenotypic shifts. Genome-resolved microbial metagenomic analyses revealed reductions in genes, microbial strains, and metabolic pathways in stressed dams that are primarily associated with pro-inflammatory function. In particular, disrupted Parasutterella excrementihominis appears to be integral to inflammatory and metabolic dysregulation during prenatal stress. Overall, these perturbations in maternal immunological and microbial regulation during pregnancy may displace immune equilibrium at the maternal-fetal interface. Notably, the absence of and reduction in overt maternal inflammation during stress indicates that the signaling patterns driving fetal outcomes in this context are more nuanced and complex than originally anticipated.

RevDate: 2020-11-21

Mostafa HH, Fissel JA, Fanelli B, et al (2020)

Metagenomic Next-Generation Sequencing of Nasopharyngeal Specimens Collected from Confirmed and Suspect COVID-19 Patients.

mBio, 11(6):.

Metagenomic next-generation sequencing (mNGS) offers an agnostic approach for emerging pathogen detection directly from clinical specimens. In contrast to targeted methods, mNGS also provides valuable information on the composition of the microbiome and might uncover coinfections that may associate with disease progression and impact prognosis. To evaluate the use of mNGS for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and/or other infecting pathogens, we applied direct Oxford Nanopore long-read third-generation metatranscriptomic and metagenomic sequencing. Nasopharyngeal (NP) swab specimens from 50 patients under investigation for CoV disease 2019 (COVID-19) were sequenced, and the data were analyzed by the CosmosID bioinformatics platform. Further, we characterized coinfections and the microbiome associated with a four-point severity index. SARS-CoV-2 was identified in 77.5% (31/40) of samples positive by RT-PCR, correlating with lower cycle threshold (Ct) values and fewer days from symptom onset. At the time of sampling, possible bacterial or viral coinfections were detected in 12.5% of SARS-CoV-2-positive specimens. A decrease in microbial diversity was observed among COVID-19-confirmed patients (Shannon diversity index, P = 0.0082; Chao richness estimate, P = 0.0097; Simpson diversity index, P = 0.018), and differences in microbial communities were linked to disease severity (P = 0.022). Furthermore, statistically significant shifts in the microbiome were identified among SARS-CoV-2-positive and -negative patients, in the latter of whom a higher abundance of Propionibacteriaceae (P = 0.028) and a reduction in the abundance of Corynebacterium accolens (P = 0.025) were observed. Our study corroborates the growing evidence that increased SARS-CoV-2 RNA detection from NP swabs is associated with the early stages rather than the severity of COVID-19. Further, we demonstrate that SARS-CoV-2 causes a significant change in the respiratory microbiome. This work illustrates the utility of mNGS for the detection of SARS-CoV-2, for diagnosing coinfections without viral target enrichment or amplification, and for the analysis of the respiratory microbiome.IMPORTANCE SARS-CoV-2 has presented a rapidly accelerating global public health crisis. The ability to detect and analyze viral RNA from minimally invasive patient specimens is critical to the public health response. Metagenomic next-generation sequencing (mNGS) offers an opportunity to detect SARS-CoV-2 from nasopharyngeal (NP) swabs. This approach also provides information on the composition of the respiratory microbiome and its relationship to coinfections or the presence of other organisms that may impact SARS-CoV-2 disease progression and prognosis. Here, using direct Oxford Nanopore long-read third-generation metatranscriptomic and metagenomic sequencing of NP swab specimens from 50 patients under investigation for COVID-19, we detected SARS-CoV-2 sequences by applying the CosmosID bioinformatics platform. Further, we characterized coinfections and detected a decrease in the diversity of the microbiomes in these patients. Statistically significant shifts in the microbiome were identified among COVID-19-positive and -negative patients, in the latter of whom a higher abundance of Propionibacteriaceae and a reduction in the abundance of Corynebacterium accolens were observed. Our study also corroborates the growing evidence that increased SARS-CoV-2 RNA detection from NP swabs is associated with the early stages of disease rather than with severity of disease. This work illustrates the utility of mNGS for the detection and analysis of SARS-CoV-2 from NP swabs without viral target enrichment or amplification and for the analysis of the respiratory microbiome.

RevDate: 2020-11-21

Zheng J, Reed E, Ramachandran P, et al (2020)

Taxonomic and Functional Shifts in Sprout Spent Irrigation Water Microbiome in Response to Salmonella Contamination of Alfalfa Seeds.

Applied and environmental microbiology pii:AEM.01811-20 [Epub ahead of print].

Despite recent advances in Salmonella-sprout research, little is known about the relationship between Salmonella and the sprout microbiome during sprouting. Sprout spent irrigation water (SSIW) provides an informative representation of the total microbiome of this primarily aquaponic crop. This study was designed to characterize the function and taxonomy of the most actively transcribed genes in SSIW from Salmonella Cubana contaminated alfalfa seeds throughout the sprouting process. Genomic DNA and total RNA from SSIW was collected at regular intervals and sequenced using Illumina Miseq and NextSeq platforms. Nucleic acid data were annotated using four different pipelines. Both metagenomic and metatranscriptomic analyses revealed a diverse and highly dynamic SSIW microbiome. A 'core' SSIW microbiome comprised Klebsiella, Enterobacter, Pantoea, and Cronobacter The impact, however, of Salmonella contamination on alfalfa seeds influenced SSIW microbial community dynamics not only structurally but also functionally. Changes in genes associated with metabolism, genetic information processing, environmental information processing, and cellular processes were abundant and time dependent. At time points of 24 h, 48 h, and 96 h, a total of 541, 723, and 424 S Cubana genes, respectively, were transcribed at either higher or lower levels compared with S Cubana at 0 h in SSIW during sprouting. An array of S Cubana genes (107) were induced at all three time points including genes involved in biofilm formation and modulation, stress responses, and virulence and tolerance to antimicrobials. Taken together, these findings expand our understanding of the effect of Salmonella seed contamination on the sprout crop microbiome and metabolome.IMPORTANCE Interactions of human enteric pathogens like Salmonella with plants and plant microbiomes remain to be elucidated. The rapid development of next generation sequencing technologies provides powerful tools enabling investigation of such interactions from broader and deeper perspectives. Using metagenomic and metatranscriptomic approaches, this study not only identified the changes in microbiome structure of SSIW associated with sprouting, but also the changes in the gene expression patterns related to the sprouting process in response to Salmonella contamination of alfalfa seeds. This study advances our knowledge on Salmonella-plant (i.e., sprouts) interaction.

RevDate: 2020-11-21

Draper LA, Ryan FJ, Dalmasso M, et al (2020)

Autochthonous faecal viral transfer (FVT) impacts the murine microbiome after antibiotic perturbation.

BMC biology, 18(1):173 pii:10.1186/s12915-020-00906-0.

BACKGROUND: It has become increasingly accepted that establishing and maintaining a complex and diverse gut microbiota is fundamental to human health. There are growing efforts to identify means of modulating and influencing the microbiota, especially in individuals who have experienced a disruption in their native microbiota. Faecal microbiota transplantation (FMT) is one method that restores diversity to the microbiota of an individual by introducing microbes from a healthy donor. FMT introduces the total microbial load into the recipient, including the bacteria, archaea, yeasts, protists and viruses. In this study, we investigated whether an autochthonous faecal viral transfer (FVT), in the form of a sterile faecal filtrate, could impact the recovery of a bacteriome disrupted by antibiotic treatment.

RESULTS: Following antibiotic disruption of the bacteriome, test mice received an FVT harvested prior to antibiotic treatment, while control mice received a heat- and nuclease-treated FVT. In both groups of mice, the perturbed microbiome reverted over time to one more similar to the pre-treatment one. However, the bacteriomes of mice that received an FVT, in which bacteriophages predominate, separated from those of the control mice as determined by principal co-ordinate analysis (PCoA). Moreover, analysis of the differentially abundant taxa indicated a closer resemblance to the pre-treatment bacteriome in the test mice that had received an FVT. Similarly, metagenomic sequencing of the virome confirmed that faecal bacteriophages of FVT and control mice differed over time in both abundance and diversity, with the phages constituting the FVT persisting in mice that received them.

CONCLUSIONS: An autochthonous virome transfer reshaped the bacteriomes of mice post-antibiotic treatment such that they more closely resembled the pre-antibiotic microbiota profile compared to mice that received non-viable phages. Thus, FVT may have a role in addressing antibiotic-associated microbiota alterations and potentially prevent the establishment of post-antibiotic infection. Given that bacteriophages are biologically inert in the absence of their host bacteria, they could form a safe and effective alternative to whole microbiota transplants that could be delivered during/following perturbation of the gut flora.

RevDate: 2020-11-20

Dougas G, Tsakris A, Billinis C, et al (2020)

Molecular detection of Rickettsia felis in common fleas in Greece and comparative evaluation of genotypic methods.

Journal of microbiological methods pii:S0167-7012(20)30820-4 [Epub ahead of print].

INTRODUCTION: Rickettsia felis is the causative agent of flea-borne spotted fever (FBSF), an emerging zoonosis. Although there is evidence of FBSF in Greece, fleas, the classic vectors of R. felis, have not been adequately studied. Thus, the aim of this study was to detect and characterize bacteria of genus Rickettsia and especially R. felis from common fleas parasitizing domestic cats and dogs in Greece and evaluate the efficiency of established molecular techniques.

MATERIALS AND METHODS: DNA of flea-pools (samples) by animal-host was investigated by quantitative real-time PCRs (qPCR), and 16S metagenomics (16S). Determination of Rickettsia spp., Rickettsia felis-like organisms (RFLOs), and R. felis was based on a combination of qPCRs targeting gltA and ompB genes, 16S automated metagenomics and manual comparison of 16S sequences for >99% similarity with the publicly available 16S R. felis GenBank sequences using the Basic Local Alignment Search Tool (BLAST>99). Information for the animal-hosts was available and statistically analyzed.

RESULTS: Among 100 flea-pools, R. felis was detected in 14 samples with a combination of six, five and three assays in 10, two and two samples, respectively. The sensitivity of the assays for Rickettsia genus (16S, and genus specific qPCRs) ranged from 62.5% to 93.8% and the specificity from 65.0% to 100%. R. felis-targeting qPCRs for gltA and ompB demonstrated sensitivity and specificity of 92.9% and 100%, and 100.0% and 87.5%, respectively. 16S metagenomics using the assay software was not able to identify R. felis positive specimens, although manual BLAST>99 did identify the species, but demonstrated sensitivity of 92.9% and specificity of 65.0%. No association of the detection rate of Rickettsia genus or R. felis, with the epidemiological data collected, was identified.

CONCLUSIONS: These observations suggest the occurrence of R. felis in fleas from pets in Attica, Greece, but PCR and sequencing assays varied considerably in sensitivity and specificity and a consensus methodology for assigning the positivity status is required to be established.

RevDate: 2020-11-20

Azar MM, Schlaberg R, Malinis MF, et al (2020)

Added Diagnostic Utility Of Clinical Metagenomics For The Diagnosis Of Pneumonia In Immunocompromised Adults.

Chest pii:S0012-3692(20)35153-9 [Epub ahead of print].

BACKGROUND: In the evaluation of community-acquired pneumonia, 30-60% of cases remain undiagnosed, despite extensive conventional microbiologic testing (CMT). Clinical metagenomics (CM) is an unbiased pathogen detection method that can increase diagnostic yield.

RESEARCH QUESTION: Does adding clinical metagenomics to conventional microbiologic testing improve the diagnostic yield for pneumonia in immunocompromised adults?

STUDY DESIGN AND METHODS: We performed a non-interventional prospective study of immunocompromised adults with pneumonia who underwent bronchoscopy and bronchoalveolar lavage (BAL) over 2-years. CMT was performed per standard of care. A commercial CM test (Explify™ Respiratory) was performed on residual BAL fluid. Final microbiologic diagnoses were based on CMT vs. CMT + CM. Final clinical diagnoses were made based on laboratory results in conjunction with clinical and radiological findings and interpreted using CMT vs. CMT+CM. Hypothetical impact of CMT+CM on management and antimicrobial stewardship was also assessed.

RESULTS: A total of 30 immunocompromised adult patients (31 episodes of pneumonia) were included. Final microbiologic diagnoses were made in 11 cases (35%) using CMT and in 18 cases (58%) using CMT+CM. Bacterial pneumonia was diagnosed in 5 cases (16%) by CMT and in 13 cases (42%) by CMT+CM, fungal pneumonia in 6 cases (19%) by CMT and in 7 cases (23%) by CMT+CM and viral pneumonia in 2 cases (6%) by CMT and in 5 cases (16%) by CMT+CM. The hypothetical impact of CMT+CM on management was deemed probable in 1 case, possible in 8 and unlikely in 2 whereas the impact on antimicrobial stewardship was possible in 13 cases and unlikely in 7. Final clinical diagnoses were made in 20/31 cases (65%) based on CMT and in 23/31 cases (74%) based on CMT+CM.

INTERPRETATION: CMT+CM increased diagnostic yield in immunocompromised adults with pneumonia from 35% to 58%, mostly by detecting additional bacterial etiologies but was less useful for fungal pneumonia.

RevDate: 2020-11-20

Münch PC, Franzosa EA, Stecher B, et al (2020)

Identification of Natural CRISPR Systems and Targets in the Human Microbiome.

Cell host & microbe pii:S1931-3128(20)30573-4 [Epub ahead of print].

Many bacteria resist invasive DNA by incorporating sequences into CRISPR loci, which enable sequence-specific degradation. CRISPR systems have been well studied from isolate genomes, but culture-independent metagenomics provide a new window into their diversity. We profiled CRISPR loci and cas genes in the body-wide human microbiome using 2,355 metagenomes, yielding functional and taxonomic profiles for 2.9 million spacers by aligning the spacer content to each sample's metagenome and corresponding gene families. Spacer and repeat profiles agree qualitatively with those from isolate genomes but expand their diversity by approximately 13-fold, with the highest spacer load present in the oral microbiome. The taxonomy of spacer sequences parallels that of their source community, with functional targets enriched for viral elements. When coupled with cas gene systems, CRISPR-Cas subtypes are highly site and taxon specific. Our analysis provides a comprehensive collection of natural CRISPR-cas loci and targets in the human microbiome.

RevDate: 2020-11-20

Akinola SA, Ayangbenro AS, OO Babalola (2020)

The diverse functional genes of maize rhizosphere microbiota assessed using shotgun metagenomics.

Journal of the science of food and agriculture [Epub ahead of print].

BACKGROUND: The geographical diversification in chemical, biological and physical properties of plant's biosphere instigates heterogenicity in the proliferation of important soil microbiome. Controlling functions and structure of plant rhizosphere due to better understanding and prediction of plant's immediate environment will help assess plant-microbe interplay, improve the productivity of plant ecosystems and improve plant response to adverse soil conditions. Here we characterized functional genes of the microbial community of maize rhizosphere using a culture-independent method.

RESULTS: Our metadata showed microbial genes involved in nitrogen fixation, phosphate solubilization, quorum sensing molecules, trehalose, siderophore production, phenazine biosynthesis protein, daunorubicin resistance, acetoin, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, 4-hydroxybenzoate, disease control and stress-reducing genes (superoxidase dismutase, catalase, peroxidase etc.). Beta-diversity showed that there is a high significant difference between most of the genes mined from rhizosphere soil samples and surrounding soils.

CONCLUSION: The high relative abundance of stress-reducing genes mined from this study showed that the sampling sites harbor not only important plant-beneficial organisms but also a hotspot for developing bio-fertilizers. Nevertheless, since most of these organisms are unculturable, mapping-out cultivation strategies for their growth could make them readily available as bio-inoculants and possible biotechnological applications in the future. This article is protected by copyright. All rights reserved.

RevDate: 2020-11-20

Curiel-Maciel NF, Martínez-Morales F, Licea-Navarro AF, et al (2020)

Characterization of Enterobacter cloacae BAGM01 Producing a Thermostable and Alkaline-Tolerant Rhamnolipid Biosurfactant from the Gulf of Mexico.

Marine biotechnology (New York, N.Y.) pii:10.1007/s10126-020-10006-3 [Epub ahead of print].

The search for novel biosurfactants (Bs) requires the isolation of microorganisms from different environments. The Gulf of Mexico (GoM) is a geographical area active in the exploration and exploitation of hydrocarbons. Recent metagenomic and microbiologic studies in this area suggested a potential richness for novel Bs microbial producers. In this work, nineteen bacterial consortia from the GoM were isolated at different depths of the water column and marine sediments. Bs production from four bacterial consortia was detected by the CTAB test and their capacity to reduce surface tension (ST), emulsion index (EI24), and hemolytic activity. These bacterial consortia produced Bs in media supplemented with kerosene, diesel, or sucrose. Cultivable bacteria from these consortia were isolated and identified by bacterial polyphasic characterization. In some consortia, Enterobacter cloacae was the predominant specie. E. cloacae BAGM01 presented Bs activity in minimal medium and was selected to improve its Bs production using a Taguchi and Box-Behnken experimental design; this strain was able to grow and presented Bs activity at 35 g L-1 of NaCl. This Bs decreased ST to around 34.5 ± 0.56 mNm-1 and presented an EI24 of 71 ± 1.27%. Other properties of this Bs were thermal stability, stability in alkaline conditions, and stability at high salinity, conferring important and desirable characteristics in multiple industries. The analysis of the genome of E. cloacae BAGM01 showed the presence of rhlAB genes that have been reported in the synthesis of rhamnolipids, and alkAB genes that are related to the degradation of alkanes. The bioactive molecule was identified as a rhamnolipid after HPLC derivatization, 1H NMR, and UPLC-QTOF-MS analysis.

RevDate: 2020-11-20

Thornton CN, Tanner WD, VanDerslice JA, et al (2020)

Localized effect of treated wastewater effluent on the resistome of an urban watershed.

GigaScience, 9(11):.

BACKGROUND: Wastewater treatment is an essential tool for maintaining water quality in urban environments. While the treatment of wastewater can remove most bacterial cells, some will inevitably survive treatment to be released into natural environments. Previous studies have investigated antibiotic resistance within wastewater treatment plants, but few studies have explored how a river's complete set of antibiotic resistance genes (the "resistome") is affected by the release of treated effluent into surface waters.

RESULTS: Here we used high-throughput, deep metagenomic sequencing to investigate the effect of treated wastewater effluent on the resistome of an urban river and the downstream distribution of effluent-associated antibiotic resistance genes and mobile genetic elements. Treated effluent release was found to be associated with increased abundance and diversity of antibiotic resistance genes and mobile genetic elements. The impact of wastewater discharge on the river's resistome diminished with increasing distance from effluent discharge points. The resistome at river locations that were not immediately downstream from any wastewater discharge points was dominated by a single integron carrying genes associated with resistance to sulfonamides and quaternary ammonium compounds.

CONCLUSIONS: Our study documents variations in the resistome of an urban watershed from headwaters to a major confluence in an urban center. Greater abundances and diversity of antibiotic resistance genes are associated with human fecal contamination in river surface water, but the fecal contamination effect seems to be localized, with little measurable effect in downstream waters. The diverse composition of antibiotic resistance genes throughout the watershed suggests the influence of multiple environmental and biological factors.

RevDate: 2020-11-20

Das Kangabam R, Silla Y, Goswami G, et al (2020)

Bacterial Operational Taxonomic Units Replace the Interactive Roles of Other Operational Taxonomic Units Under Strong Environmental Changes.

Current genomics, 21(7):512-524.

Background: Microorganisms are an important component of an aquatic ecosystem and play a critical role in the biogeochemical cycle which influences the circulation of the materials and maintains the balance in aquatic ecosystems.

Objective: The seasonal variation along with the impact of anthropogenic activities, water quality, bacterial community composition and dynamics in the Loktak Lake, the largest freshwater lake of North East India, located in the Indo-Burma hotspot region was assessed during post-monsoon and winter season through metagenome analysis.

Methods: Five soil samples were collected during Post-monsoon and winter season from the Loktak Lake that had undergone different anthropogenic impacts. The metagenomic DNA of the soil samples was extracted using commercial metagenomic DNA extraction kits following the manufacturer's instruction. The extracted DNA was used to prepare the NGS library and sequenced in the Illumina MiSeq platform.

Results: Metagenomics analysis reveals Proteobacteria as the predominant community followed by Acidobacteria and Actinobacteria. The presence of these groups of bacteria indicates nitrogen fixation, oxidation of iron, sulfur, methane, and source of novel antibiotic candidates. The bacterial members belonging to different groups were involved in various biogeochemical processes, including fixation of carbon and nitrogen, producing streptomycin, gramicidin and perform oxidation of sulfur, sulfide, ammonia, and methane.

Conclusion: The outcome of this study provides a valuable dataset representing a seasonal profile across various land use and analysis, targeting at establishing an understanding of how the microbial communities vary across the land use and the role of keystone taxa. The findings may contribute to searches for microbial bio-indicators as biodiversity markers for improving the aquatic ecosystem of the Loktak Lake.

RevDate: 2020-11-20

Patil PC, Panchal PS, Madiwale S, et al (2020)

An analysis of non-cultivable bacteria using WEKA.

Bioinformation, 16(8):620-624 pii:97320630016620.

The study of metagenomics from high throughput sequencing data processed through Waikato Environment for Knowledge Analysis (WEKA) is gaining momentum in recent years. Therefore, we report an analysis of metagenome data generated using T-RFLP followed by using the SMO (Sequential minimal optimization) algorithm in WEKA to identify the total amount of cultured and uncultured microorganism present in the sample collected from multiple sources.

RevDate: 2020-11-20

Alreshidi MM, Veettil VN, Noumi E, et al (2020)

Description of microbial diversity associated with ticks Hyalomma dromedarii (Acari: Ixodidae) isolated from camels in Hail region (Saudi Arabia) using massive sequencing of 16S rDNA.

Bioinformation, 16(8):602-610 pii:97320630016602.

Ticks are blood feeder able to transmit a wide diversity of microbes including pathogens. Therefore, it is of our interest to detect the diversity of microorganisms residing within ticks using massive sequencing of 16S rDNA. In this study, 200 adult ticks were collected from healthy camels in two localities from Hail province (Saudi Arabia). The analysis showed high microbial diversity dominated by the two domains (Archaea and Bacteria) associated with Hyalomma dromedarii from both regions. Proteobacteria (61.3%) and Firmicutes (31.2%) dominated the ticks from the Al Khotha region. While, the microbiome of ticks from the Al Gayed region was dominated by Proteobacteria (81.2%) and Firmicutes (9.2%). Twenty-three families were identified in the DNA-pool from the Al Gayed region, and was dominated by Pseudomonadaceae (45.37%), and Marinobacteraceae (14.39%) families. Francisellaceae (46%), Staphylococcaceae (24.26%) dominated the microbiome of the ticks collected from Al Gayed region. Thus, the genera Pseudomonas, Francisella, Proteus, Marinobacter, Glutamicibacter, Pedobacter, and Staphylococcus are largely distributed in the two identified microbiomes. This study concluded that ticks collected from the studied localities contained a wide range of microbial communities. These data have a great veterinary and medical importance in near future.

RevDate: 2020-11-20

Kwok KTT, de Rooij MMT, Messink AB, et al (2020)

Genome Sequences of Seven Megrivirus Strains from Chickens in The Netherlands.

Microbiology resource announcements, 9(47):.

We report seven chicken megrivirus genome sequences identified in chicken fecal samples from a broiler farm in The Netherlands. The sequences were determined using metagenomic sequencing and would expand our understanding of the genome diversity of megriviruses.

RevDate: 2020-11-20

Chang-Graham AL, Perry JL, Engevik MA, et al (2020)

Rotavirus induces intercellular calcium waves through ADP signaling.

Science (New York, N.Y.), 370(6519):.

Rotavirus causes severe diarrheal disease in children by broadly dysregulating intestinal homeostasis. However, the underlying mechanism(s) of rotavirus-induced dysregulation remains unclear. We found that rotavirus-infected cells produce paracrine signals that manifested as intercellular calcium waves (ICWs), observed in cell lines and human intestinal enteroids. Rotavirus ICWs were caused by the release of extracellular adenosine 5'-diphosphate (ADP) that activated P2Y1 purinergic receptors on neighboring cells. ICWs were blocked by P2Y1 antagonists or CRISPR-Cas9 knockout of the P2Y1 receptor. Blocking the ADP signal reduced rotavirus replication, inhibited rotavirus-induced serotonin release and fluid secretion, and reduced diarrhea severity in neonatal mice. Thus, rotavirus exploited paracrine purinergic signaling to generate ICWs that amplified the dysregulation of host cells and altered gastrointestinal physiology to cause diarrhea.

RevDate: 2020-11-20

Coutinho FH, Cabello-Yeves PJ, Gonzalez-Serrano R, et al (2020)

New viral biogeochemical roles revealed through metagenomic analysis of Lake Baikal.

Microbiome, 8(1):163 pii:10.1186/s40168-020-00936-4.

BACKGROUND: Lake Baikal is the largest body of liquid freshwater on Earth. Previous studies have described the microbial composition of this habitat, but the viral communities from this ecosystem have not been characterized in detail.

RESULTS: Here, we describe the viral diversity of this habitat across depth and seasonal gradients. We discovered 19,475 bona fide viral sequences, which are derived from viruses predicted to infect abundant and ecologically important taxa that reside in Lake Baikal, such as Nitrospirota, Methylophilaceae, and Crenarchaeota. Diversity analysis revealed significant changes in viral community composition between epipelagic and bathypelagic zones. Analysis of the gene content of individual viral populations allowed us to describe one of the first bacteriophages that infect Nitrospirota, and their extensive repertoire of auxiliary metabolic genes that might enhance carbon fixation through the reductive TCA cycle. We also described bacteriophages of methylotrophic bacteria with the potential to enhance methanol oxidation and the S-adenosyl-L-methionine cycle.

CONCLUSIONS: These findings unraveled new ways by which viruses influence the carbon cycle in freshwater ecosystems, namely, by using auxiliary metabolic genes that act upon metabolisms of dark carbon fixation and methylotrophy. Therefore, our results shed light on the processes through which viruses can impact biogeochemical cycles of major ecological relevance. Video Abstract.

RevDate: 2020-11-20

Żaczek M, Weber-Dąbrowska B, Międzybrodzki R, et al (2020)

Phage Prevalence in the Human Urinary Tract-Current Knowledge and Therapeutic Implications.

Microorganisms, 8(11): pii:microorganisms8111802.

Recent metagenomic analyses imply an immense abundance of phages in the human body. Samples collected from different sites (lungs, skin, oral cavity, intestines, ascitic fluid, and urine) reveal a generally greater number of phage particles than that of eukaryotic viruses. The presence of phages in those tissues and fluids reflects the paths they must overcome in the human body, but may also relate to the health statuses of individuals. Besides shaping bacterial metabolism and community structure, the role of phages circulating in body fluids has not been fully understood yet. The lack of relevant reports is especially visible with regard to the human urobiome. Certainly, phage presence and the role they have to fulfill in the human urinary tract raises questions on potential therapeutic connotations. Urinary tract infections (UTIs) are among the most common bacterial infections in humans and their treatment poses a difficult therapeutic dilemma. Despite effective antibiotic therapy, these infections tend to recur. In this review, we summarized the recent data on phage presence in the human urinary tract and its possible implications for health and disease.

RevDate: 2020-11-19

Kalvari I, Nawrocki EP, Ontiveros-Palacios N, et al (2020)

Rfam 14: expanded coverage of metagenomic, viral and microRNA families.

Nucleic acids research pii:5992291 [Epub ahead of print].

Rfam is a database of RNA families where each of the 3444 families is represented by a multiple sequence alignment of known RNA sequences and a covariance model that can be used to search for additional members of the family. Recent developments have involved expert collaborations to improve the quality and coverage of Rfam data, focusing on microRNAs, viral and bacterial RNAs. We have completed the first phase of synchronising microRNA families in Rfam and miRBase, creating 356 new Rfam families and updating 40. We established a procedure for comprehensive annotation of viral RNA families starting with Flavivirus and Coronaviridae RNAs. We have also increased the coverage of bacterial and metagenome-based RNA families from the ZWD database. These developments have enabled a significant growth of the database, with the addition of 759 new families in Rfam 14. To facilitate further community contribution to Rfam, expert users are now able to build and submit new families using the newly developed Rfam Cloud family curation system. New Rfam website features include a new sequence similarity search powered by RNAcentral, as well as search and visualisation of families with pseudoknots. Rfam is freely available at https://rfam.org.

RevDate: 2020-11-19

Nascimento FSD, Suzuki MO, Taba JV, et al (2020)

Analysis of biliary MICRObiota in hepatoBILIOpancreatic diseases compared to healthy people [MICROBILIO]: Study protocol.

PloS one, 15(11):e0242553 pii:PONE-D-20-22918.

BACKGROUND: The performance of the microbiota is observed in several digestive tract diseases. Therefore, reaching the biliary microbiota may suggest ways for studies of biomarkers, diagnoses, tests and therapies in hepatobiliopancreatic diseases.

METHODS: Bile samples will be collected in endoscopic retrograde cholangiopancreatography patients (case group) and living liver transplantation donors (control group). We will characterize the microbiome based on two types of sequence data: the V3/V4 regions of the 16S ribosomal RNA (rRNA) gene and total shotgun DNA. For 16S sequencing data a standard 16S processing pipeline based on the Amplicon Sequence Variant concept and the qiime2 software package will be employed; for shotgun data, for each sample we will assemble the reads and obtain and analyze metagenome-assembled genomes.

RESULTS: The primary expected results of the study is to characterize the specific composition of the biliary microbiota in situations of disease and health. In addition, it seeks to demonstrate the existence of changes in the case of illness and also possible disease biomarkers, diagnosis, interventions and therapies in hepatobiliopancreatic diseases.

TRIAL REGISTRATION: NCT04391426. Registered 18 May 2020, https://clinicaltrials.gov/ct2/show/NCT04391426.

RevDate: 2020-11-19

Arunasri K, Mahesh M, Sai Prashanthi G, et al (2020)

Mycobiome changes in the vitreous of post fever retinitis patients.

PloS one, 15(11):e0242138 pii:PONE-D-20-14908.

Fungi have been associated with various diseases of the eye like keratitis, uveitis and endophthalmitis. Despite this fact, fungal microbiome (mycobiome) studies compared to the bacterial microbiome studies have remained neglected. In the present study, using metagenomic sequencing, the mycobiomes of the vitreous of healthy control individuals (VC, n = 15) and individuals with post fever retinitis + non-PFR uveitis (PFR+, n = 9) were analysed and compared. The results indicated that Ascomycota was the most predominant phylum in both VC and PFR+ groups. Further, at the genera level it was observed that the abundance of 17 fungal genera were significantly different in post fever retinitis (PFR, n = 6) group compared to control group. Of these 17 genera, it was observed that 14 genera were relatively more abundant in PFR group and the remaining 3 genera in the VC group. Genus Saccharomyces, a commensal of the gut and skin, was predominantly present in the vitreous of both the cohorts, however it was significantly less abundant in PFR group. Further, significant increase in the genera that have a pathogenic interaction with the host were observed in PFR group. On the whole the mycobiome in both the groups differed significantly and formed two distinct clusters in the heatmap and Principal co-ordinate analysis. These results demonstrate significant changes in the mycobiome from the vitreous of post fever retinitis patients compared to healthy controls thus implying that dysbiotic changes in the fungal vitreous microbiome are associated with PFR.

RevDate: 2020-11-19

Huang K, Li Q, Sun H, et al (2020)

Metagenomic analysis revealed the sulfur- and iron- oxidation capabilities of heterotrophic denitrifying sludge.

Ecotoxicology (London, England) pii:10.1007/s10646-020-02307-z [Epub ahead of print].

Heterotrophic denitrification is widely applied in wastewater treatment processes to remove nitrate. However, the ability of the heterotrophic denitrifying sludge to use inorganic matter as electron donors to perform autotrophic denitrification has rarely been investigated. In this study, we enriched heterotrophic denitrifying sludge and demonstrated its sulfur- and iron- oxidizing abilities and denitrification performance with batch experiments. Based on high-throughput sequencing of 16S rRNA genes, high diversity and abundance of sulfur-oxidizing bacteria (SOB) (e.g., Sulfuritalea, Thiobacillus, and Thiothrix) and iron (II)-oxidizing bacteria (FeOB) (e.g., Azospira and Thiobacillus) were observed. Metagenomic sequencing and genome binning results further suggested that the SOB in the heterotrophic denitrifying sludge were mainly Alphaproteobacteria and Betaproteobacteria instead of Gammaproteobacteria and Epsilonproteobacteria. The similarities of potential iron-oxidizing genes with known sequences were very low (32-51%), indicating potentially novel FeOB species in this system. The findings of this study suggested that the heterotrophic denitrifying sludge harbors diverse mixotrophic denitrifying bacterial species, and based on this finding, we proposed that organic carbon and inorganic electron donors (e.g., sulfur, thiosulfate, and iron) could be jointly used in engineering practices according to the quality and quantity of wastewater to balance the cost and efficiency of the denitrification process.

RevDate: 2020-11-19

Perlejewski K, Pawełczyk A, Bukowska-Ośko I, et al (2020)

Search for Viral Infections in Cerebrospinal Fluid From Patients With Autoimmune Encephalitis.

Open forum infectious diseases, 7(11):ofaa468 pii:ofaa468.

Background: It has been reported that virus-mediated brain tissue damage can lead to autoimmune encephalitis (AE) characterized by the presence of antibodies against neuronal surface antigens. In the study, we investigate the presence of viruses in cerebrospinal fluid (CSF) from patients with AE using reverse transcription polymerase chain reaction (RT-PCR)/PCR and shotgun metagenomics.

Methods: CSF samples collected from 200 patients with encephalitis were tested for the presence of antibodies against antiglutamate receptor (NMDAR), contactin-associated protein 2 (CASPR2), glutamate receptors (type AMPA1/2), leucine-rich glioma-inactivated protein 1 (LGI1), dipeptidyl aminopeptidase-like protein 6 (DPPX), and GABA B receptor, and those found positive were further analyzed with real-time RT-PCR/PCR for common viral neuroinfections and shotgun DNA- and RNA-based metagenomics.

Results: Autoantibodies against neuronal cells were detected in CSF from 8 individuals (4% of all encephalitis patients): 7 (3.5%) had anti-NMDAR and 1 (0.5%) had anti-GABA B. RT-PCR/PCR identified human herpes virus type 1 (HSV-1; 300 copies/mL) and the representative of Enterovirus genus (550 copies/mL) in 1 patient each. Torque teno virus (TTV) was found in another patient using metagenomic analysis, and its presence was confirmed by specific PCR.

Conclusions: We detected the presence of HSV, TTV, and Enterovirus genus in CSF samples from 3 out of 8 AE patients. These findings support the concept of viral involvement in the pathogenesis of this disease.

RevDate: 2020-11-19

Pelikan C, Wasmund K, Glombitza C, et al (2020)

Anaerobic bacterial degradation of protein and lipid macromolecules in subarctic marine sediment.

The ISME journal pii:10.1038/s41396-020-00817-6 [Epub ahead of print].

Microorganisms in marine sediments play major roles in marine biogeochemical cycles by mineralizing substantial quantities of organic matter from decaying cells. Proteins and lipids are abundant components of necromass, yet the taxonomic identities of microorganisms that actively degrade them remain poorly resolved. Here, we revealed identities, trophic interactions, and genomic features of bacteria that degraded 13C-labeled proteins and lipids in cold anoxic microcosms containing sulfidic subarctic marine sediment. Supplemented proteins and lipids were rapidly fermented to various volatile fatty acids within 5 days. DNA-stable isotope probing (SIP) suggested Psychrilyobacter atlanticus was an important primary degrader of proteins, and Psychromonas members were important primary degraders of both proteins and lipids. Closely related Psychromonas populations, as represented by distinct 16S rRNA gene variants, differentially utilized either proteins or lipids. DNA-SIP also showed 13C-labeling of various Deltaproteobacteria within 10 days, indicating trophic transfer of carbon to putative sulfate-reducers. Metagenome-assembled genomes revealed the primary hydrolyzers encoded secreted peptidases or lipases, and enzymes for catabolism of protein or lipid degradation products. Psychromonas species are prevalent in diverse marine sediments, suggesting they are important players in organic carbon processing in situ. Together, this study provides new insights into the identities, functions, and genomes of bacteria that actively degrade abundant necromass macromolecules in the seafloor.

RevDate: 2020-11-19

Ishida S, Kato K, Tanaka M, et al (2020)

Genome-wide association studies and heritability analysis reveal the involvement of host genetics in the Japanese gut microbiota.

Communications biology, 3(1):686 pii:10.1038/s42003-020-01416-z.

Numerous host extrinsic and intrinsic factors affect the gut microbiota composition, but their cumulative effects do not sufficiently explain the variation in the microbiota, suggesting contributions of missing factors. The Japanese population possesses homogeneous genetic features suitable for genome-wide association study (GWAS). Here, we performed GWASs for human gut microbiota using 1068 healthy Japanese adults. To precisely evaluate genetic effects, we corrected for the impacts of numerous host extrinsic and demographic factors by introducing them as covariates, enabling us to discover five loci significantly associated with microbiome diversity measures: HS3ST4, C2CD2, 2p16.1, 10p15.1, and 18q12.2. Nevertheless, these five variants explain only a small fraction of the variation in the gut microbiota. We subsequently investigated the heritability of each of the 21 core genera and found that the abundances of six genera are heritable. We propose that the gut microbiota composition is affected by a highly polygenic architecture rather than several strongly associated variants in the Japanese population.

RevDate: 2020-11-19

Hugerth LW, Pereira M, Zha Y, et al (2020)

Assessment of In Vitro and In Silico Protocols for Sequence-Based Characterization of the Human Vaginal Microbiome.

mSphere, 5(6):.

The vaginal microbiome has been connected to a wide range of health outcomes. This has led to a thriving research environment but also to the use of conflicting methodologies to study its microbial composition. Here, we systematically assessed best practices for the sequencing-based characterization of the human vaginal microbiome. As far as 16S rRNA gene sequencing is concerned, the V1-V3 region performed best in silico, but limitations of current sequencing technologies meant that the V3-V4 region performed equally well. Both approaches presented very good agreement with qPCR quantification of key taxa, provided that an appropriate bioinformatic pipeline was used. Shotgun metagenomic sequencing presents an interesting alternative to 16S rRNA gene amplification and sequencing but requires deeper sequencing and more bioinformatic expertise and infrastructure. We assessed different tools for the removal of host reads and the taxonomic annotation of metagenomic reads, including a new, easy-to-build and -use reference database of vaginal taxa. This curated database performed as well as the best-performing previously published strategies. Despite the many advantages of shotgun sequencing, none of the shotgun approaches assessed here agreed with the qPCR data as well as the 16S rRNA gene sequencing.IMPORTANCE The vaginal microbiome has been connected to various aspects of host health, including susceptibility to sexually transmitted infections as well as gynecological cancers and pregnancy outcomes. This has led to a thriving research environment but also to conflicting available methodologies, including many studies that do not report their molecular biological and bioinformatic methods in sufficient detail to be considered reproducible. This can lead to conflicting messages and delay progress from descriptive to intervention studies. By systematically assessing best practices for the characterization of the human vaginal microbiome, this study will enable past studies to be assessed more critically and assist future studies in the selection of appropriate methods for their specific research questions.

RevDate: 2020-11-19

Claesen J, Spagnolo JB, Ramos SF, et al (2020)

A Cutibacterium acnes antibiotic modulates human skin microbiota composition in hair follicles.

Science translational medicine, 12(570):.

The composition of the skin microbiota varies widely among individuals when sampled at the same body site. A key question is which molecular factors determine strain-level variability within sub-ecosystems of the skin microbiota. Here, we used a genomics-guided approach to identify an antibacterial biosynthetic gene cluster in Cutibacterium acnes (formerly Propionibacterium acnes), a human skin commensal bacterium that is widely distributed across individuals and skin sites. Experimental characterization of this biosynthetic gene cluster resulted in identification of a new thiopeptide antibiotic, cutimycin. Analysis of individual human skin hair follicles revealed that cutimycin contributed to the ecology of the skin hair follicle microbiota and helped to reduce colonization of skin hair follicles by Staphylococcus species.

RevDate: 2020-11-19

Adamberg K, Vilu R, V Pazienza (2020)

Inhibition of pyruvate dehydrogenase kinase influence microbiota and metabolomic profile in pancreatic cancer xenograft mice.

BMC research notes, 13(1):540 pii:10.1186/s13104-020-05384-9.

OBJECTIVE: Despite recent advances in treatment options, pancreatic cancer remains the most deadly major cancer. Targeting metabolism represents an emerging anti-cancer strategy.

RESULTS: Metagenomic 16S analysis was employed to explore the effect of Dichloroacetate (DCA) on the composition of the fecal microbiota and metabolomic profile was assessed on in vivo pancreatic cancer mouse xenograft model. Pancreatic cancer xenograft mice displayed a shift of microbiota' profile as compared to control mice without DCA treatment and a significant decrease of the purine bases inosine xanthine together with their metabolically-related compound hypoxanthine were observed in the DCA treated group as compared to the control group. Two aminoacids methionine and aspartic acid resulted decreased and increased respectively. DCA affects tumor environment and studies are needed in order to understand whether DCA supplementation could be supportive as synergistic approach to enhance the efficacy of existing cancer treatments in pancreatic cancer patients.

RevDate: 2020-11-19

Wei L, Zeng B, Zhang S, et al (2020)

Inbreeding Alters the Gut Microbiota of the Banna Minipig.

Animals : an open access journal from MDPI, 10(11): pii:ani10112125.

The gut microbiota coevolve with the host and can be stably transmitted to the offspring. Host genetics plays a crucial role in the composition and abundance of gut microbiota. Inbreeding can cause a decrease of the host's genetic diversity and the heterozygosity. In this study, we used 16S rRNA gene sequencing to compare the differences of gut microbiota between the Diannan small-ear pig and Banna minipig inbred, aiming to understand the impact of inbreeding on the gut microbiota. Three dominant bacteria (Stenotrophlomonas, Streptococcus, and Lactobacillus) were steadily enriched in both the Diannan small-ear pig and Banna minipig inbred. After inbreeding, the gut microbiota alpha diversity and some potential probiotics (Bifidobacterium, Tricibacter, Ruminocaccae, Christensenellaceae, etc.) were significantly decreased, while the pathogenic Klebsiella bacteria was significantly increased. In addition, the predicted metagenomic analysis (PICRUSt2) indicated that several amino acid metabolisms (''Valine, leucine, and isoleucine metabolism'', ''Phenylalanine, tyrosine, and tryptophan biosynthesis'', ''Histidine metabolism'') were also markedly decreased after the inbreeding. Altogether our data reveal that host inbreeding altered the composition and the predicted function of the gut microbiome, which provides some data for the gut microbiota during inbreeding.

RevDate: 2020-11-18

Beraud-Martínez LK, Gómez-Gil B, Franco-Nava MÁ, et al (2020)

A metagenomic assessment of microbial communities in anaerobic bioreactors and sediments: taxonomic and functional relationships.

Anaerobe pii:S1075-9964(20)30152-9 [Epub ahead of print].

The present study used metagenomic sequencing, metagenome assembly and physical-chemical analysis to describe taxonomically and functionally 3 anaerobic bioreactors treating manure (LI), brewery (BR) and cornmeal (CO) wastes, and an anaerobic estuarine sediment (ES). Proteobacteria, Firmicutes, Euryarchaeota and Bacteroidetes were the most abundant Phyla in all metagenomes. A bacteria/archaea ratio of 3.4 was found in the industrial full-scale anaerobic bioreactors BR and CO, while ratios greater than 10 were found for LI and ES. Canonical correspondence analysis showed that environmental variables such as chemical oxygen demand, lipid content, and ammonium nitrogen influenced the ordination of taxonomic groups. Mesotoga prima was linked to high-temperature conditions, particularly in the BR bioreactor, along with the presence of heat shock proteins genes. Likewise, the hydrogenotrophic methanogen, Methanoregula formicica, was associated with high ammonium concentration in LI bioreactor. The interactions of microbes with specific methanogenic pathways were identified using Clusters of Orthologous Groups (COG) functions, while metagenome-assembled genomes (MAGs) further confirmed relationships between taxa and functions. Our results provide valuable information to understand microbial processes in anaerobic environments.

RevDate: 2020-11-18

Hunnam JC, Jerrett IV, Mee PT, et al (2020)

An idiopathic upper alimentary tract ulcerative syndrome in weaned dairy calves in Victoria, Australia.

Transboundary and emerging diseases [Epub ahead of print].

An idiopathic clinical syndrome had been described in weaned dairy calves in the state of Victoria, Australia, where affected animals presented with diarrhoea, ill-thrift, enteritis and ulceration of the upper alimentary tract, with occasional oral/nasal ulcers. Between 7 November 2016 and 31 March 2019, 34 Victorian cattle herds were investigated after each reported five or more weaned calves with diarrhoea and/or ill-thrift, or at least one calf with oral/nasal ulceration. Primary study objectives included the development of a detailed case definition for the clinical syndrome, termed Upper Alimentary tract Ulcerative Syndrome (UAUS), and the identification of potential causative virus(es) using metagenomics. A diagnosis of UAUS could not be made based solely on clinical signs and required histopathological assessment of post-mortem samples. Specifically, this included the identification of multifocal to coalescing areas of mucosal epithelial necrosis at all depths of the stratified squamous epithelium of the oesophagus, along with exclusion of bovine viral diarrhoea virus. Based on this case definition, twelve herds were diagnosed with clinical UAUS across the three dairying regions of Victoria, while thirteen were ruled UAUS-negative. The status of the nine remaining herds was unresolved due to a lack of required post-mortem samples. Metatranscriptomic analysis on oral swabs and oesopharyngeal samples from confirmed UAUS cases did not detect a virus common to the cross-sectional sample collection.

RevDate: 2020-11-18

Gureev AP, Syromyatnikov MY, Ignatyeva DA, et al (2020)

Effect of long-term methylene blue treatment on the composition of mouse gut microbiome and its relationship with the cognitive abilities of mice.

PloS one, 15(11):e0241784 pii:PONE-D-20-10817.

In recent years, methylene blue (MB) has attracted considerable interest as a potential drug for the treatment of methemoglobinemia and neurodegenerative diseases. MB is active against microorganisms from various taxonomic groups. However, no studies have yet been conducted on the effect of MB on the intestinal microbiome of model animals. The aim of this work was to study the effect of different concentrations of MB on the mouse gut microbiome and its relationship with the cognitive abilities of mice. We showed that a low MB concentration (15 mg/kg/day) did not cause significant changes in the microbiome composition. The Bacteroidetes/Firmicutes ratio decreased relative to the control on the 2nd and 3rd weeks. A slight decrease in the levels Actinobacteria was detected on the 3rd week of the experiment. Changes in the content of Delta, Gamma, and Epsilonproteobacteria have been also observed. We did not find significant alterations in the composition of intestinal microbiome, which could be an indication of the development of dysbiosis or other gut dysfunction. At the same time, a high concentration of MB (50 mg/kg/day) led to pronounced changes, primarily an increase in the levels of Delta, Gamma and Epsilonproteobacteria. Over 4 weeks of therapy, the treatment with high MB concentration has led to an increase in the median content of Proteobacteria to 7.49% vs. 1.61% in the control group. Finally, we found that MB at a concentration of 15 mg/kg/day improved the cognitive abilities of mice, while negative correlation between the content of Deferribacteres and cognitive parameters was revealed. Our data expand the understanding of the relationship between MB, cognitive abilities, and gut microbiome in respect to the antibacterial properties of MB.

RevDate: 2020-11-18

Erdem G, Kaptsan I, Sharma H, et al (2020)

Cerebrospinal Fluid Analysis for Viruses by Metagenomic Next-Generation Sequencing in Pediatric Encephalitis: Not Yet Ready for Prime Time?.

Journal of child neurology [Epub ahead of print].

BACKGROUND: Metagenomic next-generation sequencing offers an unbiased approach to identifying viral pathogens in cerebrospinal fluid of patients with meningoencephalitis of unknown etiology.

METHODS: In an 11-month case series, we investigated the use of cerebrospinal fluid metagenomic next-generation sequencing to diagnose viral infections among pediatric hospitalized patients presenting with encephalitis or meningoencephalitis of unknown etiology. Cerebrospinal fluid from patients with known enterovirus meningitis were included as positive controls. Cerebrospinal fluid from patients with primary intracranial hypertension were included to serve as controls without known infections.

RESULTS: Cerebrospinal fluid metagenomic next-generation sequencing was performed for 37 patients. Among 27 patients with encephalitis or meningoencephalitis, 4 were later diagnosed with viral encephalitis, 6 had non-central nervous system infections with central nervous system manifestations, 6 had no positive diagnostic tests, and 11 were found to have a noninfectious diagnosis. Metagenomic next-generation sequencing identified West Nile virus (WNV) in the cerebrospinal fluid of 1 immunocompromised patient. Among the 4 patients with known enterovirus meningitis, metagenomic next-generation sequencing correctly identified enteroviruses and characterized the viral genotype. No viral sequences were detected in the cerebrospinal fluid of patients with primary intracranial hypertension. Metagenomic next-generation sequencing also identified sequences of nonpathogenic torque Teno virus in cerebrospinal fluid specimens from 13 patients.

CONCLUSIONS: Our results showed viral detection by cerebrospinal fluid metagenomic next-generation sequencing only in 1 immunocompromised patient and did not offer a diagnostic advantage over conventional testing. Viral phylogenetic characterization by metagenomic next-generation sequencing could be used in epidemiologic investigations of some viral pathogens, such as enteroviruses. The finding of torque Teno viruses in cerebrospinal fluid by metagenomic next-generation sequencing is of unknown significance but may merit further exploration for a possible association with noninfectious central nervous system disorders.

RevDate: 2020-11-18

Zhang L, Li C, Zhai Y, et al (2020)

Analysis of the vaginal microbiome of giant pandas using metagenomics sequencing.

MicrobiologyOpen [Epub ahead of print].

In this study, a total of 14 vaginal samples (GPV1-14) from giant pandas were analyzed. These vaginal samples were divided into two groups as per the region and age of giant pandas. All the vaginal samples were analyzed using metagenomic sequencing. As per the outcomes of metagenomic analysis, Proteobacteria (39.04%), Firmicutes (5.27%), Actinobacteria (2.94%), and Basidiomycota (2.77%) were found to be the dominant phyla in the microbiome of the vaginal samples. At the genus level, Pseudomonas (21.90%) was found to be the most dominant genus, followed by Streptococcus (3.47%), Psychrobacter (1.89%), and Proteus (1.38%). Metastats analysis of the microbial species in the vaginal samples of giant pandas from Wolong Nature Reserve, Dujiangyan and Ningbo Youngor Zoo, and Ya'an Bifengxia Nature Reserve was found to be significantly different (p < 0.05). Age groups, that is, AGE1 (5-10 years old) and AGE2 (11-16 years old), also demonstrated significantly different inter-group microbial species (p < 0.05). For the first time, Chlamydia and Neisseria gonorrhoeae were detected in giant pandas' reproductive tract. GPV3 vaginal sample (2.63%) showed highest Chlamydia content followed by GPV14 (0.91%), and GPV7 (0.62%). GPV5 vaginal sample (7.17%) showed the highest Neisseria gonorrhoeae content, followed by GPV14 (7.02%), and GPV8 (6.50%). Furthermore, we employed eggNOG, CAZy, KEGG, and NCBI databases to investigate the functional significance of giant panda's vaginal microbial community. The outcomes indicated that giant panda's vaginal microbes were involved in biological processes. The data from this study will help in improving the reproductive health of giant pandas.

RevDate: 2020-11-18

Davis BC, Riquelme MV, Ramirez-Toro G, et al (2020)

Demonstrating an Integrated Antibiotic Resistance Gene Surveillance Approach in Puerto Rican Watersheds Post-Hurricane Maria.

Environmental science & technology [Epub ahead of print].

Comprehensive surveillance approaches are needed to assess sources, clinical relevance, and mobility of antibiotic resistance genes (ARGs) in watersheds. Here, we examined metrics derived from shotgun metagenomic sequencing and relationship to human fecal markers (HFMs; crAssphage, enterococci) and anthropogenic antibiotic resistance markers (AARMs; intI1, sul1) in three distinct Puerto Rican watersheds as a function of adjacent land use and wastewater treatment plant (WWTP) input 6 months after Hurricane Maria, a category V storm. Relative abundance and diversity of total ARGs increased markedly downstream of WWTP inputs, with ARGs unique to WWTP and WWTP-impacted river samples predominantly belonging to the aminoglycoside and β-lactam resistance classes. WWTP and other anthropogenic inputs were similarly associated with elevated resistome risk scores and mobility incidence (M%). Contig analysis indicated a wide variety of mobile β-lactam ARGs associated with pathogens downstream of WWTP discharge that were consistent with regional clinical concern, e.g., Klebsiella pneumoniae contigs containing KPC-2 within an ISKpn6-like transposase. HFMs and AARMs correlated strongly with the absolute abundance of total ARGs, but AARMs better predicted the majority of ARGs in general (85.4 versus <2%) and β-lactam ARGs in particular. This study reveals sensitive, quantitative, mobile, clinically relevant, and comprehensive targets for antibiotic resistance surveillance in watersheds.

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ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin (and even a collection of poetry — Chicago Poems by Carl Sandburg).

Timelines

ESP now offers a much improved and expanded collection of timelines, designed to give the user choice over subject matter and dates.

Biographies

Biographical information about many key scientists.

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are now being automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 07 JUL 2018 )