Escherichia coli Serotype O55:H7 Diversity Supports Parallel Acquisition of Bacteriophage at Shiga Toxin Phage Insertion Sites during Evolution of the O157:H7 Lineage
| Autor: | Kimberly Nguyen, Olga Petrauskene, Craig T. Parker, Steven Huynh, Manohar R. Furtado, Beatriz Quiñones, Robert E. Mandrell, Elizabeth Newton, Craig Cummings, Melissa Barker, Lovorka Degoricija, Ronak Patel, Robert S. Tebbs, Rixun Fang, Samar Fontanoz, Paolo Vatta, Jennifer L. Kyle, Michelle Swimley |
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| Rok vydání: | 2012 |
| Předmět: |
DNA
Bacterial Genetic Markers Serotype Lineage (evolution) Molecular Sequence Data Virulence Escherichia coli O157 Microbiology Genome Shiga Toxin Bacteriophage Enteropathogenic Escherichia coli Phylogenetics Bacteriophages Serotyping Molecular Biology Phylogeny Genetics biology Genetic Variation Shiga toxin Articles Gene Expression Regulation Bacterial Chromosomes Bacterial biology.organism_classification DNA Transposable Elements biology.protein Genome Bacterial |
| Zdroj: | Journal of Bacteriology. 194:1885-1896 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.00120-12 |
| Popis: | Enteropathogenic Escherichia coli (EPEC) continues to be a leading cause of mortality and morbidity in children around the world. Two EPEC genomes have been fully sequenced: those of EPEC O127:H6 strain E2348/69 (United Kingdom, 1969) and EPEC O55:H7 strain CB9615 (Germany, 2003). The O55:H7 serotype is a recent precursor to the virulent enterohemorrhagic E. coli O157:H7. To explore the diversity of O55:H7 and better understand the clonal evolution of O157:H7, we fully sequenced EPEC O55:H7 strain RM12579 (California, 1974), which was collected 1 year before the first U.S. isolate of O157:H7 was identified in California. Phage-related sequences accounted for nearly all differences between the two O55:H7 strains. Additionally, O55:H7 and O157:H7 strains were tested for the presence and insertion sites of Shiga toxin gene ( stx )-containing bacteriophages. Analysis of non-phage-associated genes supported core elements of previous O157:H7 stepwise evolutionary models, whereas phage composition and insertion analyses suggested a key refinement. Specifically, the placement and presence of lambda-like bacteriophages (including those containing stx ) should not be considered stable evolutionary markers or be required in placing O55:H7 and O157:H7 strains within the stepwise evolutionary models. Additionally, we suggest that a 10.9-kb region (block 172) previously believed unique to O55:H7 strains can be used to identify early O157:H7 strains. Finally, we defined two subsets of O55:H7 strains that share an as-yet-unobserved or extinct common ancestor with O157:H7 strains. Exploration of O55:H7 diversity improved our understanding of the evolution of E. coli O157:H7 and suggested a key revision to accommodate existing and future configurations of stx -containing bacteriophages into current models. |
| Databáze: | OpenAIRE |
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