Genome signatures of Escherichia coli O157:H7 isolates from the bovine host reservoir
| Autor: | Mark Eppinger, Jacques Ravel, Joseph E. LeClerc, Mark K. Mammel, Thomas A. Cebula |
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| Rok vydání: | 2011 |
| Předmět: |
DNA
Bacterial Genetic Markers Lineage (genetic) Molecular Sequence Data Virulence Cattle Diseases Human pathogen Biology medicine.disease_cause Escherichia coli O157 Applied Microbiology and Biotechnology Genome Phylogenetics medicine Animals Evolutionary and Genomic Microbiology Escherichia coli Escherichia coli Infections Phylogeny Genetics Polymorphism Genetic Ecology Shiga toxin Sequence Analysis DNA biology.protein Cattle Niche adaptation Food Science Biotechnology |
| Zdroj: | Applied and environmental microbiology. 77(9) |
| ISSN: | 1098-5336 |
| Popis: | Cattle comprise a main reservoir of Shiga toxin-producing Escherichia coli O157:H7 (STEC). The significant differences in host prevalence, transmissibility, and virulence phenotypes among strains from bovine and human sources are of major interest to the public health community and livestock industry. Genomic analysis revealed divergence into three lineages: lineage I and lineage I/II strains are commonly associated with human disease, while lineage II strains are overrepresented in the asymptomatic bovine host reservoir. Growing evidence suggests that genotypic differences between these lineages, such as polymorphisms in Shiga toxin subtypes and synergistically acting virulence factors, are correlated with phenotypic differences in virulence, host ecology, and epidemiology. To assess the genomic plasticity on a genome-wide scale, we have sequenced the whole genome of strain EC869, a bovine-associated E. coli O157:H7 isolate. Comparative phylogenomic analysis of this key isolate enabled us to place accurately bovine lineage II strains within the genetically homogenous E. coli O157:H7 clade. Identification of polymorphic loci that are anchored both in the chromosomal backbone and horizontally acquired regions allowed us to associate bovine genotypes with altered virulence phenotypes and host prevalence. This study catalogued numerous novel lineage II-specific genome signatures, some of which appear to be associated intimately with the altered pathogenic potential and niche adaptation within the bovine rumen. The presented extended list of polymorphic markers is valuable in the development of a robust typing system critical for forensic, diagnostic, and epidemiological studies of this emerging human pathogen. |
| Databáze: | OpenAIRE |
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