<i>Escherichia coli </i>serotype O55:H7 diversity supports parallel acquisition of bacteriophage at Shiga toxin phage insertion sites during evolution of the O157:H7 lineage
Submitted by Beatriz Quiñones on
PDF version| Title | Escherichia coli serotype O55:H7 diversity supports parallel acquisition of bacteriophage at Shiga toxin phage insertion sites during evolution of the O157:H7 lineage |
| Publication Type | Journal Article |
| Year of Publication | 2012 |
| Authors | Kyle, JL, Cummings, CA, Parker, CT, Quiñones, B, Vatta, P, Newton, E, Huynh, S, Swimley, M, Degoricija, L, Barker, M, Fontanoz, S, Nguyen, K, Patel, R, Fang, R, Tebbs, R, Petrauskene, O, Furtado, M, Mandrell, RE |
| Journal | J BacteriolJ BacteriolJ Bacteriol |
| Volume | 194 |
| Pagination | 1885-96 |
| Date Published | Apr |
| ISBN Number | 1098-5530 (Electronic)0021-9193 (Linking) |
| Accession Number | 22328665 |
| Abstract | 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. |
| Short Title | Journal of bacteriologyJournal of bacteriology |
| Alternate Journal | Journal of bacteriology |
