Comparative genomic analysis of a multiple antimicrobial resistant enterotoxigenic E. coli O157 lineage from Australian pigs

• DOI: 10.1186/s12864-015-1382-y
• Publication Date: 2015-03-09T22:40:55Z
• Authors: Ethan Wyrsch; Piklu Roy Chowdhury; Sam Abraham; Jerran Santos; Aaron E Darling; Ian G Charles; Toni A Chapman; Steven P Djordjevic
• Keywords: Enterotoxigenic Escherichia coli; Lineage (genetic)

Enterotoxigenic Escherichia coli (ETEC) are a major economic threat to pig production globally, with serogroups O8, O9, O45, O101, O138, O139, O141, O149 and O157 implicated as the leading diarrhoeal pathogens affecting pigs below four weeks of age. A multiple antimicrobial resistant ETEC (O157 SvETEC) representative isolates from farm in New South Wales, Australia that experienced repeated bouts pre- post-weaning diarrhoea resulting fatalities was characterized here. Enterohaemorrhagic E. (EHEC) O157:H7 cause both sporadic widespread outbreaks foodborne disease, predominantly have ruminant origin belong ST11 clonal complex. Here, for first time, we conducted comparative genomic analyses two epidemiologically-unrelated porcine, disease-causing O157; SvETEC O157:K88 734/3, examined their phylogenetic relationship EHEC O157:H7. 734/3 novel sequence type (ST4245) comprises part ST23 complex genetically distinct O157. Comparative analysis using PhyloSift shows group into single clade most similar extraintestinal avian pathogenic (APEC) isolate O78 clusters within Genome content highly between SvETEC, APEC O78, variability limited laterally acquired elements, including prophages, plasmids resistance gene loci. Putative virulence factors, toxins STb LT K88 (F4) adhesin, were conserved 734/3. The also encoded heat stable enterotoxin STa second allele STb, whilst prophage serum survival bor. Both harbor large repertoire antibiotic genes but association mobile elements remains undetermined. We present an draft genome sequences epidemiologically-unrelated, phylogenetically lineages reside