Biology subjects

Simner, P. J.

Publications and source records attributed to Simner, P. J..

3 recordsLinked to original sources

bioRxiv2021

Prevalence, persistence, and genetics of antibody responses to protein toxins and virulence factors

Microbial exposures are crucial environmental factors that impact healthspan by sculpting the immune system and microbiota. Antibody profiling via programmable Phage ImmunoPrecipitation Sequencing (PhIP-Seq) provides a high-throughput, costeffective approach for multiplexed detection of exposure and response to thousands of microbial protein products. Here we designed and constructed a library of 95,601 56 amino acid peptide tiles spanning a subset of environmental proteins more likely to be associated with immune responses: those with "toxin" or "virulence factor" keyword annotations. PhIP-Seq was used to profile the circulating antibodies of ~1,000 individuals against this "ToxScan" library of 14,430 toxins and virulence factors from 1,312 genera of organisms. In addition to a detailed analysis of six commonly encountered human commensals and pathogens, we study the age-dependent stability of the ToxScan profile and use a genome-wide association study (GWAS) to find that the MHC-II locus modulates the selection of bacterial epitopes. We detect previously described anti-flagellin antibody responses in a Crohns disease cohort and identify a novel association between anti-flagellin antibodies and juvenile dermatomyositis (JDM). PhIP-Seq with the ToxScan library provides a new window into exposure and immune responses to environmental protein toxins and virulence factors, which can be used to study human health and disease at cohort scale.

immunology↗

bioRxiv2020

Metagenomic Next-Generation Sequencing of Rectal Swabs for the Surveillance of Antimicrobial Resistant Organisms on the Illumina Miseq and Oxford MinION Platforms

PurposeAntimicrobial resistance (AMR) is a public health threat where efficient surveillance is needed to prevent outbreaks. Existing methods for detection of gastrointestinal colonization of multidrug-resistant organisms (MDRO) are limited to specific organisms or resistance mechanisms. Metagenomic next-generation sequencing (mNGS) is a more rapid and agnostic diagnostic approach for microbiome and resistome investigations. We determined if mNGS can detect MDRO from rectal swabs in concordance with standard microbiology results. MethodsWe performed and compared mNGS performance on short-read Illumina MiSeq (N=10) and long-read Nanopore MinION (N=4) platforms directly from peri-rectal swabs to detect vancomycin-resistant enterococci (VRE) and carbapenem-resistant Gram-negative organisms (CRO). ResultsWe detected E. faecium (N=8) and E. faecalis (N=2) with associated van genes (9/10) in concordance with VRE culture-based results. We studied the microbiome and identified CRO organisms, P. aeruginosa (N=1), E. cloacae (N=1), and KPC-producing K. pneumoniae (N=1). Nanopore real-time detection detected the blaKPC gene in 2.5 minutes and provided genetic context (blaKPC harbored on pKPC_Kp46 IncF plasmid). Illumina sequencing provided accurate allelic variant determination (i.e., blaKPC-2) and strain typing of the K. pneumoniae (ST-15). Conclusions: We demonstrated an agnostic approach for surveillance of MDRO, examining advantages of both short and long-read mNGS methods for AMR detection.

microbiology↗

bioRxiv2020

A plasmid locus associated with Klebsiella clinical infections encodes a microbiome-dependent gut fitness factor

Introductory paragraphGut colonization by the pathogen Klebsiella pneumoniae (Kp) is consistently associated with subsequent Kp disease1-5, and patients are predominantly infected with their colonizing strain1,2. However, colonizing strains likely vary in their potential to cause infection. We previously identified the plasmid-encoded tellurium resistance (ter) operon as highly associated with infection when compared to asymptomatic colonization in hospitalized patients1. The ter operon bestows resistance to the toxic compound tellurite oxide (TeO3-2), but this is unlikely to be its physiological function, as tellurium and TeO3-2 are exceedingly rare. Here we show that terC is necessary and terZABCDEF is sufficient for phenotypic TeO3-2 resistance. Next, we demonstrate that ter is encoded on a diverse group of plasmids without known plasmid-encoded virulence genes, suggesting an independent role in infection. Finally, our studies indicate that ter is a gut fitness factor, and its fitness advantage is conferred only when specific gut microbiota constituents are present. Collectively, these data reveal the Kp ter operon that is highly associated with human infection likely acts early in pathogenesis as a horizontally-transferrable fitness factor promoting robust gut colonization in the presence of the indigenous microbiota.

microbiology↗