Dataset Information

Comparative phylogenomics of the food-borne pathogen Campylobacter jejuni reveals genetic markers predictive of infection source.

ABSTRACT: Campylobacter jejuni is the predominant cause of bacterial gastroenteritis worldwide, but traditional typing methods are unable to discriminate strains from different sources that cause disease in humans. We report the use of genomotyping (whole-genome comparisons of microbes using DNA microarrays) combined with Bayesian-based algorithms to model the phylogeny of this major food-borne pathogen. In this study 111 C. jejuni strains were examined by genomotyping isolates from humans with a spectrum of C. jejuni-associated disease (70 strains), chickens (17 strains), bovines (13 strains), ovines (5 strains), and the environment (6 strains). From these data, the Bayesian phylogeny of the isolates revealed two distinct clades unequivocally supported by Bayesian probabilities (P = 1); a livestock clade comprising 31/35 (88.6%) of the livestock isolates and a "nonlivestock" clade comprising further clades of environmental isolates. Several genes were identified as characteristic of strains in the livestock clade. The most prominent was a cluster of six genes (cj1321 to cj1326) within the flagellin glycosylation locus, which were confirmed by PCR analysis as genetic markers in six additional chicken-associated strains. Surprisingly these studies show that the majority (39/70, 55.7%) of C. jejuni human isolates were found in the nonlivestock clade, suggesting that most C. jejuni infections may be from nonlivestock (and possibly nonagricultural) sources. This study has provided insight into a previously unidentified reservoir of C. jejuni infection that may have implications in disease-control strategies. The comparative phylogenomics approach described provides a robust methodological prototype that should be applicable to other microbes.

SUBMITTER: Champion OL

PROVIDER: S-EPMC1276044 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Comparative phylogenomics of the food-borne pathogen Campylobacter jejuni reveals genetic markers predictive of infection source.

Champion Olivia L OL Gaunt Michael W MW Gundogdu Ozan O Elmi Abdi A Witney Adam A AA Hinds Jason J Dorrell Nick N Wren Brendan W BW

Proceedings of the National Academy of Sciences of the United States of America 20051017 44

Campylobacter jejuni is the predominant cause of bacterial gastroenteritis worldwide, but traditional typing methods are unable to discriminate strains from different sources that cause disease in humans. We report the use of genomotyping (whole-genome comparisons of microbes using DNA microarrays) combined with Bayesian-based algorithms to model the phylogeny of this major food-borne pathogen. In this study 111 C. jejuni strains were examined by genomotyping isolates from humans with a spectrum ...[more]

PMID: 16230626

Similar Datasets

Project description:Campylobacter is among the most common worldwide causes of bacterial gastroenteritis. This organism is part of the commensal microbiota of numerous host species, including livestock, and these animals constitute potential sources of human infection. Molecular typing approaches, especially multilocus sequence typing (MLST), have been used to attribute the source of human campylobacteriosis by quantifying the relative abundance of alleles at seven MLST loci among isolates from animal reservoirs and human infection, implicating chicken as a major infection source. The increasing availability of bacterial genomes provides data on allelic variation at loci across the genome, providing the potential to improve the discriminatory power of data for source attribution. Here we present a source attribution approach based on the identification of novel epidemiological markers among a reference pan-genome list of 1,810 genes identified by gene-by-gene comparison of 884 genomes of Campylobacter jejuni isolates from animal reservoirs, the environment, and clinical cases. Fifteen loci involved in metabolic activities, protein modification, signal transduction, and stress response or coding for hypothetical proteins were selected as host-segregating markers and used to attribute the source of 42 French and 281 United Kingdom clinical C. jejuni isolates. Consistent with previous studies of British campylobacteriosis, analyses performed using STRUCTURE software attributed 56.8% of British clinical cases to chicken, emphasizing the importance of this host reservoir as an infection source in the United Kingdom. However, among French clinical isolates, approximately equal proportions of isolates were attributed to chicken and ruminant reservoirs, suggesting possible differences in the relative importance of animal host reservoirs and indicating a benefit for further national-scale attribution modeling to account for differences in production, behavior, and food consumption.IMPORTANCE Accurately quantifying the relative contribution of different host reservoirs to human Campylobacter infection is an ongoing challenge. This study, based on the development of a novel source attribution approach, provides the first results of source attribution in Campylobacter jejuni in France. A systematic analysis using gene-by-gene comparison of 884 genomes of C. jejuni isolates, with a pan-genome list of genes, identified 15 novel epidemiological markers for source attribution. The different proportions of French and United Kingdom clinical isolates attributed to each host reservoir illustrate a potential role for local/national variations in C. jejuni transmission dynamics.

Dataset Information

Comparative phylogenomics of the food-borne pathogen Campylobacter jejuni reveals genetic markers predictive of infection source.

Publications

Comparative phylogenomics of the food-borne pathogen Campylobacter jejuni reveals genetic markers predictive of infection source.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets