Journal article
Virulence-associated genes in faecal and clinical Escherichia coli isolates cultured from broiler chickens in Australia
Australian veterinary journal, Vol.102(8), pp.398-406
08/2024
PMID: 38721873
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Abstract
A healthy chicken's intestinal flora harbours a rich reservoir of Escherichia coli as part of the commensal microbiota. However, some strains, known as avian pathogenic E. coli (APEC), carry specific virulence genes (VGs) that enable them to invade and cause extraintestinal infections such as avian colibacillosis. Although several VG combinations have been identified, the pathogenic mechanisms associated with APEC are ill-defined. The current study screened a subset of 88 E. coli isolates selected from 237 pre-existing isolates obtained from commercial poultry flocks in Australia. The 88 isolates were selected based on their entero-bacterial repetitive intergenic consensus (ERIC) and antimicrobial resistance (AMR) profiles and included 29 E. coli isolates cultured from chickens with colibacillosis (referred to as clinical E. coli or CEC) and 59 faecal E. coli (FEC) isolates cultured from clinically healthy chickens. The isolates were screened for the presence of 35 previously reported VGs. Of these, 34 were identified, with iucA not being detected. VGs focG, hlyA and sfa/foc were only detected in FEC isolates. Eight VGs had a prevalence of 90% or above in the CEC isolates. Specifically, astA (100%); feoB (96.6%); iutA, iss, ompT, iroN and hlyF (all 93.1%); and vat (89.7%). The prevalence of these were significantly lower in FEC isolates (astA 79.7%, feoB 77.9%, iutA 52.5%, iss 45.8%, ompT 50.9%, iroN 37.3%, hlyF 50.9% and vat 42.4%). The odds ratios that each of these eight VGs were more likely to be associated with CEC than FEC ranged from 7.8 to 21.9. These eight VGs may be used to better define APEC and diagnostically detect APEC in Australia. Further investigations are needed to identify the roles of these VGs in pathogenicity.
Details
- Title
- Virulence-associated genes in faecal and clinical Escherichia coli isolates cultured from broiler chickens in Australia
- Creators
- L. Awawdeh - Western Sydney UniversityR. Forrest - Eastern Institute of TechnologyC. Turni - The University of QueenslandR. Cobbold - The University of QueenslandJ. Henning - The University of QueenslandJ. Gibson - The University of Queensland
- Publication Details
- Australian veterinary journal, Vol.102(8), pp.398-406
- Publisher
- Wiley
- Number of pages
- 9
- Grant note
- Open access publishing facilitated by The University of Queensland, as part of the Wiley - The University of Queensland agreement via the Council of Australian University Librarians.
- Identifiers
- 991013372729602368
- Copyright
- © 2024 The Authors.
- Academic Unit
- Faculty of Science and Engineering; Veterinary Science
- Language
- English
- Resource Type
- Journal article