scholarly journals The single-species metagenome: subtyping Staphylococcus aureus core genome sequences from shotgun metagenomic data

2015 ◽  
Author(s):  
Sandeep J. Joseph ◽  
Ben Li ◽  
Robert A. Petit ◽  
Zhaohui S. Qin ◽  
Lyndsey A. Darrow ◽  
...  

AbstractMetagenome shotgun sequence projects offer the potential for large scale biogeographic analysis of microbial species. In this project we developed a method for detecting 33 common subtypes of the pathogenic bacterium Staphylococcus aureus. We used a binomial mixture model implemented in the binstrain software and the coverage counts at > 100,000 known S. aureus SNP (single nucleotide polymorphism) sites derived from prior comparative genomic analysis to estimate the proportion of each subtype in metagenome samples. Using this pipeline we were able to obtain > 87% sensitivity and > 94% specificity when testing on low genome coverage samples of diverse S. aureus strains (0.025X). We found that 321 and 149 metagenome samples from the Human Microbiome Project and metaSUB analysis of the New York City subway, respectively, contained S. aureus at genome coverage > 0.025. In both projects, CC8 and CC30 were the most common S. aureus subtypes encountered. We found evidence that the subtype composition at different body sites of the same individual were more similar than random sampling and more limited evidence that certain body sites were enriched for particular subtypes. One surprising finding was the apparent high frequency of CC398, a lineage associated with livestock, in samples from the tongue dorsum. Epidemiologic analysis of the HMP subject population suggested that high BMI (body mass index) and health insurance are risk factors for S. aureus but there was limited power to find factors linked to carriage of even the most common subtype. In the NYC subway data, we found a small signal of geographic distance affecting subtype clustering but other unknown factors influence taxonomic distribution of the species around the city. We argue that pathogen detection in metagenome samples requires the use of subtypes based on whole species population genomic analysis rather than using ad hoc collections of reference strains.

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2571 ◽  
Author(s):  
Sandeep J. Joseph ◽  
Ben Li ◽  
Robert A. Petit III ◽  
Zhaohui S. Qin ◽  
Lyndsey Darrow ◽  
...  

In this study we developed a genome-based method for detectingStaphylococcus aureussubtypes from metagenome shotgun sequence data. We used a binomial mixture model and the coverage counts at >100,000 knownS. aureusSNP (single nucleotide polymorphism) sites derived from prior comparative genomic analysis to estimate the proportion of 40 subtypes in metagenome samples. We were able to obtain >87% sensitivity and >94% specificity at 0.025X coverage forS. aureus. We found that 321 and 149 metagenome samples from the Human Microbiome Project and metaSUB analysis of the New York City subway, respectively, containedS. aureusat genome coverage >0.025. In both projects, CC8 and CC30 were the most commonS. aureusclonal complexes encountered. We found evidence that the subtype composition at different body sites of the same individual were more similar than random sampling and more limited evidence that certain body sites were enriched for particular subtypes. One surprising finding was the apparent high frequency of CC398, a lineage often associated with livestock, in samples from the tongue dorsum. Epidemiologic analysis of the HMP subject population suggested that high BMI (body mass index) and health insurance are possibly associated withS. aureuscarriage but there was limited power to identify factors linked to carriage of even the most common subtype. In the NYC subway data, we found a small signal of geographic distance affecting subtype clustering but other unknown factors influence taxonomic distribution of the species around the city.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Courtney M. Thomas ◽  
Najwa Taib ◽  
Simonetta Gribaldo ◽  
Guillaume Borrel

AbstractOther than the Methanobacteriales and Methanomassiliicoccales, the characteristics of archaea that inhabit the animal microbiome are largely unknown. Methanimicrococcus blatticola, a member of the Methanosarcinales, currently reunites two unique features within this order: it is a colonizer of the animal digestive tract and can only reduce methyl compounds with H2 for methanogenesis, a increasingly recognized metabolism in the archaea and whose origin remains debated. To understand the origin of these characteristics, we have carried out a large-scale comparative genomic analysis. We infer the loss of more than a thousand genes in M. blatticola, by far the largest genome reduction across all Methanosarcinales. These include numerous elements for sensing the environment and adapting to more stable gut conditions, as well as a significant remodeling of the cell surface components likely involved in host and gut microbiota interactions. Several of these modifications parallel those previously observed in phylogenetically distant archaea and bacteria from the animal microbiome, suggesting large-scale convergent mechanisms of adaptation to the gut. Strikingly, M. blatticola has lost almost all genes coding for the H4MPT methyl branch of the Wood–Ljungdahl pathway (to the exception of mer), a phenomenon never reported before in any member of Class I or Class II methanogens. The loss of this pathway illustrates one of the evolutionary processes that may have led to the emergence of methyl-reducing hydrogenotrophic methanogens, possibly linked to the colonization of organic-rich environments (including the animal gut) where both methyl compounds and hydrogen are abundant.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1411 ◽  
Author(s):  
Pengfan Zhang ◽  
Tao Jin ◽  
Sunil Kumar Sahu ◽  
Jin Xu ◽  
Qiong Shi ◽  
...  

Bacterial indole-3-acetic acid (IAA), an effector molecule in microbial physiology, plays an important role in plant growth-promotion. Here, we comprehensively analyzed about 7282 prokaryotic genomes representing diverse bacterial phyla, combined with root-associated metagenomic data to unravel the distribution of tryptophan-dependent IAA synthesis pathways and to quantify the IAA synthesis-related genes in the plant root environments. We found that 82.2% of the analyzed bacterial genomes were potentially capable of synthesizing IAA from tryptophan (Trp) or intermediates. Interestingly, several phylogenetically diverse bacteria showed a preferential tendency to utilize different pathways and tryptamine and indole-3-pyruvate pathways are most prevalent in bacteria. About 45.3% of the studied genomes displayed multiple coexisting pathways, constituting complex IAA synthesis systems. Furthermore, root-associated metagenomic analyses revealed that rhizobacteria mainly synthesize IAA via indole-3-acetamide (IAM) and tryptamine (TMP) pathways and might possess stronger IAA synthesis abilities than bacteria colonizing other environments. The obtained results refurbished our understanding of bacterial IAA synthesis pathways and provided a faster and less labor-intensive alternative to physiological screening based on genome collections. The better understanding of IAA synthesis among bacterial communities could maximize the utilization of bacterial IAA to augment the crop growth and physiological function.


mSphere ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Sophie L. Nixon ◽  
Rebecca A. Daly ◽  
Mikayla A. Borton ◽  
Lindsey M. Solden ◽  
Susan A. Welch ◽  
...  

ABSTRACT Bacteria of the phylum Verrucomicrobia are prevalent and are particularly common in soil and freshwater environments. Their cosmopolitan distribution and reported capacity for polysaccharide degradation suggests members of Verrucomicrobia are important contributors to carbon cycling across Earth’s ecosystems. Despite their prevalence, the Verrucomicrobia are underrepresented in isolate collections and genome databases; consequently, their ecophysiological roles may not be fully realized. Here, we expand genomic sampling of the Verrucomicrobia phylum by describing a novel genus, “Candidatus Marcellius,” belonging to the order Opitutales. “Ca. Marcellius” was recovered from a shale-derived produced fluid metagenome collected 313 days after hydraulic fracturing, the deepest environment from which a member of the Verrucomicrobia has been recovered to date. We uncover genomic attributes that may explain the capacity of this organism to inhabit a shale gas well, including the potential for utilization of organic polymers common in hydraulic fracturing fluids, nitrogen fixation, adaptation to high salinities, and adaptive immunity via CRISPR-Cas. To illuminate the phylogenetic and environmental distribution of these metabolic and adaptive traits across the Verrucomicrobia phylum, we performed a comparative genomic analysis of 31 publicly available, nearly complete Verrucomicrobia genomes. Our genomic findings extend the environmental distribution of the Verrucomicrobia 2.3 kilometers into the terrestrial subsurface. Moreover, we reveal traits widely encoded across members of the Verrucomicrobia, including the capacity to degrade hemicellulose and to adapt to physical and biological environmental perturbations, thereby contributing to the expansive habitat range reported for this phylum. IMPORTANCE The Verrucomicrobia phylum of bacteria is widespread in many different ecosystems; however, its role in microbial communities remains poorly understood. Verrucomicrobia are often low-abundance community members, yet previous research suggests they play a major role in organic carbon degradation. While Verrucomicrobia remain poorly represented in culture collections, numerous genomes have been reconstructed from metagenomic data sets in recent years. The study of genomes from across the phylum allows for an extensive assessment of their potential ecosystem roles. The significance of this work is (i) the recovery of a novel genus of Verrucomicrobia from 2.3 km in the subsurface with the ability to withstand the extreme conditions that characterize this environment, and (ii) the most extensive assessment of ecophysiological traits encoded by Verrucomicrobia genomes to date. We show that members of this phylum are specialist organic polymer degraders that can withstand a wider range of environmental conditions than previously thought.


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