Characterization of extended-spectrum b-lactamase-producing Escherichia coli isolated from fresh produce and agricultural environments in Korea

Min Hyeok Cha, Jae Gee Ryu, Young Min Chi, Gun Jo Woo

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

This study was conducted to characterize Escherichia coli strains and evaluate the spread of antimicrobial resistance among these strains from fresh produce and farm environments in Korea. We then conducted phenotypic and genetic studies on antimicrobial-resistant isolates. We determined the genetic epidemiological characteristics of isolates that produced extended-spectrum b-lactamase (ESBL) and confirmed plasmid transfer in isolates that carried blaCTX-M-type genes. E. coli strains were isolated from 8 samples of fresh produce and 152 samples from the farm environment collected from May 2014 to June 2016. Cephalosporin resistance was the most prevalent (61.8%) type of resistance among the isolates. Five ESBL-producing strains with high genetic homology with E. coli of human or livestock origin were identified. Lateral transfer of plasmids harboring blaCTX-M-type genes to transconjugants was successful. Two isolates from Chinese cabbage and from water samples collected from a nearby stream harbored the ISEcp1-blaCTX-M-55-orf477 operon and were confirmed as sequence type 1196 and the same type of plasmid replicon, suggesting that cross-contamination was highly likely. A high-risk clone of sequence type 69 (clonal complex 69) isolates was also recovered from the farm environment. This study provides genetic evidence that antimicrobial resistance factors in E. coli from farm environments originate in the clinic or in livestock, highlighting the fact that good agricultural practices in farming are important to inhibit the spread of antimicrobial resistance to bacteria on fresh produce.

Original languageEnglish
Pages (from-to)1115-1124
Number of pages10
JournalJournal of Food Protection
Volume83
Issue number7
DOIs
Publication statusPublished - 2020 Jul

Keywords

  • Antimicrobial resistance
  • CTX-M-type genes
  • Escherichia coli
  • Extended-spectrum b-lactamase
  • Farm environment
  • Fresh produce

ASJC Scopus subject areas

  • Food Science
  • Microbiology

Fingerprint

Dive into the research topics of 'Characterization of extended-spectrum b-lactamase-producing Escherichia coli isolated from fresh produce and agricultural environments in Korea'. Together they form a unique fingerprint.

Cite this