title: Prevalence of extended-spectrum-β-lactamase-producing Escherichia coli from pigs at slaughter in the UK in 2013.
abstract: OBJECTIVE
  To determine the prevalence and types of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli occurring in pigs at slaughter in the UK in 2013.
  
  
  METHODS
  Caecal samples from 637 pigs, sampled via a UK-wide monitoring programme in 2013, were enriched overnight in buffered peptone water, before plating to CHROMagar CTX and Oxoid Brilliance ESBL agar. Presumptive ESBL-producing E. coli from both media were tested for ESBL phenotype using MAST ESβL ID discs. Isolates with an ESBL phenotype were examined for the presence of blaCTX-M, blaOXA, blaSHV and blaTEM genes using a multiplex PCR. All blaCTX-M and blaSHV genes identified by PCR were sequenced.
  
  
  RESULTS
  A total of 23.4% (95% CI 19.2-27.6) of pigs were positive for ESBL-producing E. coli; 22% (95% CI 17.8-26.1) of the pigs carried E. coli producing CTX-M enzymes [comprising enzyme types 1 (18.7% of pigs), 3 (0.2%), 14 (0.5%), 15 (1.4%), 27 (0.5%), 32 (0.5%) and 55 (0.3%)] and 2.2% (95% CI 0.8-3.6) of the pigs carried E. coli producing SHV-12. Five pigs carried both CTX-M- and SHV-12-producing E. coli as different isolates. There were no statistically significant differences observed between the two medium types in terms of the proportions of each CTX-M enzyme type isolated.
  
  
  CONCLUSIONS
  In this UK study, 23.4% of pigs were found to be positive for ESBL-producing E. coli using selective culture media. The use of two different commercially available ESBL isolation media was found to improve the detection of ESBL-producing E. coli.
authors.affiliation: Animal Health and Veterinary Laboratories Agency (Weybridge), Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK luke.randall@ahvla.gsi.gov.uk.
authors.forename: L P
authors.initials: LP
authors.lastname: Randall
authors.affiliation: Animal Health and Veterinary Laboratories Agency (Weybridge), Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: F
authors.initials: F
authors.lastname: Lemma
authors.affiliation: Animal Health and Veterinary Laboratories Agency (Bury St Edmunds), Southgate Street, Bury St Edmunds IP33 2BD, UK.
authors.forename: J P
authors.initials: JP
authors.lastname: Rogers
authors.affiliation: Animal Health and Veterinary Laboratories Agency (Weybridge), Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: T E A
authors.initials: TE
authors.lastname: Cheney
authors.affiliation: Animal Health and Veterinary Laboratories Agency (Weybridge), Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: L F
authors.initials: LF
authors.lastname: Powell
authors.affiliation: Animal Health and Veterinary Laboratories Agency (Shrewsbury), Kendal Road, Shrewsbury SY1 4HD, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Teale
mesh_terms: D000003:Abattoirs / Q000592:standards*; D000818:Animals; D004926:Escherichia coli / Q000201:enzymology* / Q000302:isolation & purification*; D008137:Longitudinal Studies; D015995:Prevalence; D013552:Swine / Q000382:microbiology*; D006113:United Kingdom; D001618:beta-Lactamases / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D001618:beta-Lactamases
keywords: CTX-M; ESBLs; SHV; cephalosporins; resistance