title: Survival capabilities of Escherichia coli O26 isolated from cattle and clinical sources in Australia to disinfectants, acids and antimicrobials.
abstract: After E. coli O157, E. coli O26 is the second most prevalent enterohaemorrhagic E. coli (EHEC) serotype identified in cases of foodborne illness in Australia and throughout the world. E. coli O26 associated foodborne outbreaks have drawn attention to the survival capabilities of this organism in a range of environments. The aim of the present study was to assess the ability of E. coli O26 to survive the effects of disinfectants, acids and antimicrobials and investigate the possible influence of virulence genes in survival and persistence of E. coli O26 from human and cattle sources from Australia.
  
  
  
  Initial characterization indicated that E. coli O26 are a genetically diverse group that were shown to belong to a number of pathotypes. Overall, 86.4% of isolates were susceptible to all antimicrobials tested with no significant differences in resistance observed between pathotypes. A representative subset of isolates (n = 40) were selected to determine their ability to survive disinfectants at proposed industry working concentrations and acid stress. Profoam, Kwiksan 22, and Topactive DES. were able to inhibit the growth of 100% of isolates. The remaining three disinfectants (Dairy Chlor 12.5%, Envirosan and Maxifoam) were not effective against the subset of 40 E. coli O26. Finally, elevated MICs (1,024 to 4,096 μg/ml) of acetic, propionic, lactic, and citric acids were determined for the majority of the isolates (85%).
  
  
  
  Australian E. coli O26 isolates belong to a range of pathotypes that harbor differing virulence markers. Despite this, their response to antimicrobials, disinfectants and acids is similar confirming that stress response appears unrelated to the presence of EHEC virulence markers. Notwithstanding, the tolerance to disinfectants and the elevated acid MICs for EHEC and the other E. coli O26 pathotypes examined in this study may contribute to bacterial colonization on food contact surfaces and subsequent foodborne illness caused by this pathogen.
authors.affiliation: School of Natural Sciences, Griffith University, Brisbane, QLD, Australia. salmaaibsais.lajhar@griffithuni.edu.au.|CSIRO Agriculture and Food, Brisbane, QLD, Australia. salmaaibsais.lajhar@griffithuni.edu.au.|Present address: CSIRO Agriculture and Food, 39 Kessels Rd, Coopers Plains, QLD, 4108, Australia. salmaaibsais.lajhar@griffithuni.edu.au.
authors.forename: Salma A
authors.initials: SA
authors.lastname: Lajhar
authors.affiliation: School of Natural Sciences, Griffith University, Brisbane, QLD, Australia.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Brownlie
authors.affiliation: CSIRO Agriculture and Food, Brisbane, QLD, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Barlow
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D000143:Acids / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001315:Australia; D001483:Base Sequence; D002417:Cattle; D019343:Citric Acid / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics; D004202:Disinfectants / Q000008:administration & dosage / Q000494:pharmacology*; D054324:Enterohemorrhagic Escherichia coli / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D005516:Food Microbiology; D005517:Foodborne Diseases; D006801:Humans; D019344:Lactic Acid / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000379:methods; D009713:Nucleotidyltransferases / Q000235:genetics; D016133:Polymerase Chain Reaction; D015995:Prevalence; D011422:Propionates / Q000494:pharmacology; D013315:Stress, Psychological; D013534:Survival; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000143:Acids; D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D004202:Disinfectants; D011422:Propionates; D037521:Virulence Factors; D019343:Citric Acid; D019344:Lactic Acid; D009713:Nucleotidyltransferases; C020587:glucose-1-phosphate thymidylyltransferase; C029658:propionic acid; D019342:Acetic Acid
keywords: Antimicrobial agent; Disinfectant; E. coli O26; Organic acid; Pathotype; Virulence marker