Occurrence of extended spectrum β-lactamase and AmpC genes among multidrug-resistant Escherichia coli and emergence of ST131 from poultry meat in Thailand

This study investigated the prevalence of antibiotic-resistant Escherichia coli using extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase as exemplars of multidrug-resistant phenotypes in poultry meat samples taken from open-air and supermarkets in Phitsanulok province, Northern Thailand. Two hundred and fifty poultry meat samples from open-air (n = 147) and supermarkets (n = 103) were analyzed. In total, 143 cefotaxime-resistant E. coli isolates comprising 78 isolates (53.1%) from open-air markets and 65 isolates (63.1%) from supermarkets were obtained. No significant difference could be observed in the prevalence of ESBL-positive E. coli between samples taken from open-air (70.5%) and supermarkets (69.2%). ESBL genotypes comprised of bla(CTX-M-group 1) (69%), bla(CTX-M-group 9) (13%), bla(TEM-116) (1%), bla(SHV-2a) (1%) and bla(SHV-12) (1%) were detected. 39.5% of the ESBL-negative E. coli possessed bla(CMY-2). The bla(CTX-M-group 1), bla(CTX-M-group 9) and bla(CMY-2) were successfully transferred into E. coli by conjugation at high frequencies. Repetitive palindromic-PCR of some bla(CTX-M) and bla(CMY-2)-positive E. coli isolates revealed identical DNA patterns suggesting clonal spread. Phylogenetic grouping and MLST analysis revealed that 3 isolates were E. coli ST131. Of these, 2 isolates were ESBL-negative and carried bla(CMY-2). The other isolate was ESBL-positive and carried bla(TEM-116). This is the first study to demonstrate ESBL and AmpC genotypes in E. coli and the first discovery of human pathogen ST131 from Thai poultry meat. Our data raises serious concerns for food safety and biosecurity in the Thai food industry. Crown Copyright (C) 2017 Published by Elsevier Ltd. All rights reserved.