Evaluation of meat, fruit and vegetables from retail stores in five United Kingdom regions as sources of extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant Escherichia coli

We determined the prevalence and types of extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant Escherichia coil in raw retail beef, chicken, pork, fruit and vegetables in five UK regions in 2013-14. Raw meat (n = 397), and fruit and vegetable samples (n = 400) were purchased from retail stores in London, East Anglia, North West England, Scotland and Wales. Samples were tested for the presence of ESBL-producing E. coil by plating enriched samples on CHROMagar CTX and CHROMagar ESBL, for AmpC-type E. coil by plating on "CHROMagar FOX" (CHROMagar ECC + 16 mg/L cefoxitin), and for carbapenem-resistant E. coli by plating on CHROMagar KPC. Additionally, pre-enrichment counts were performed on the above agars, and on CHROMagar ECC. Isolates of interest were characterised by MALDI-ToF to confirm identification, by PCR for bla(CIT), bla(CTX-M), bla(OXA), bla(SHV) and bla(TEM) genes; ESBL or bla(CIT) genes were sequenced. Only 1.9% and 2.5% of beef and pork samples, respectively were positive for ESBL-producing E. coil after enrichment compared with 65.4% of chicken samples. 85.6% positive samples from chicken meat carried bla(CTX-M-1); bla(CTX-M-15) was not detected. None of the fruits or vegetables yielded ESBL-producing E. coil and none of the meat, fruit or vegetable samples yielded carbapenem-resistant E. coli. Retail chicken was more frequently a source of ESBL-producing E. coil than were beef, pork, fruit or vegetables. None of the foodstuffs yielded E. coil with CDC-M-15 ESBL, which dominates in human clinical isolates in the UK, and none yielded carbapenem-resistant E. coli. Crown Copyright (C) 2016 Published by Elsevier B.V. All rights reserved.