Draft Genome Sequence of an Escherichia coli O157:H43 Strain Isolated from Cattle

Abstract

Here we report the draft genome sequence of an Escherichia coli O157:H43 strain, designated T22, with an atypical virulence gene profile and isolated from healthy cattle. T22 produces cytolethal distending toxin V (CDT-V) and belongs to phylogenetic group B1 and sequence type 155 (ST155).

No evidence for a bovine mastitis Escherichia coli pathotype

“…EPEC [47]. Interestingly, the bovine commensal O157:H43 isolate T22, even though belonging to the O157 serotype, is not a member of phylogroup E, but of group B1 [48], providing an example for horizontal transfer of O-antigen genes. Finally, phylogroup B2 is the most diverse phylogroup, based on nucleotide and gene content.…”

“…O80:H45 4750 89 [34,40] D6-117.07 MAEC A (10, 10) O45:H11 4477 51 [34,40] [33] MPEC4839 MAEC A (10, 10) O105:H32 4502 124 This study, [39] MPEC4969 MAEC B1 (1125,161) O139:H19 4468 130 This study, [39] O157:H43 T22 milk comme nsal B1 (155,58) O157:H43 4792 64 [41][42][43] O32:H37 P4 MAEC A (10, 10) O32:H37 4581 72 [32,44] P4 The 25 E. coli genomes of the bovine-associated strain panel were mostly associated with phylogroups A and B1 (13 and 10, respectively; Table 1). Most of the MAEC (11/16, 69%) belong to phylogroup A and the majority of commensal strains to group B1 (6/9, 67%).…”

Sequence Variability of P2-Like Prophage Genomes Carrying the Cytolethal Distending Toxin V Operon in Escherichia coli O157

“…The potential recombination of prophages in E. coli O157 was already reported (28), and it was also suggested that the mosaic structure of prophages is the result of extensive exchange of genetic material among different bacteriophages and also their hosts (13), like in the case of lambdoid prophages harboring the cdt-I and cdt-IV operons (13,14). The genome sequencing project of strain T22 (29) confirmed that the integration site of the prophage is between the cpxP and fieF genes. This is the same site where P2-like prophages can be found in a further four E. coli strains according to publicly available GenBank entries (accession no.…”

Cytolethal distending toxin producing Escherichia coli O157:H43 strain T22 represents a novel evolutionary lineage within the O157 serogroup

“…E. coli O157 strains harboring eae gene but no stx were categorized as enteropathogenic E. coli (EPEC), such strains were isolated from human and animal sources (Stephan et al, 2004, Tóth et al, 2009. Additionally, atypical O157 strains, which carry none of the key virulence genes were reported (Sváb et al, 2013b;Tóth et al, 2009).…”

“…Earlier, we reported the draft genome of a CDT-V producing atypical E. coli O157:H43 strain (T22, Sváb et al, 2013b). In the current study, our goals were to determine the complete genome of T22 and to investigate its phylogenetic relation to publicly available E. coli genomes.…”