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Detection of plasmid-mediated quinolone resistance genes in β-lactamase-producing Escherichia coli isolates from

K W Seo1, Y J Lee1

  • 1College of Veterinary Medicine, Kyungpook National University, Daegu 41566, Republic of Korea.

Poultry Science
|November 30, 2018
PubMed

Insights

Layer hens carry multidrug-resistant Escherichia coli with plasmid-mediated quinolone resistance (PMQR) genes. These resistant bacteria can transfer to the food chain, highlighting the need for surveillance in poultry farming.

Area of Science:

  • Veterinary Microbiology
  • Antimicrobial Resistance
  • Food Safety

Background:

  • Escherichia coli isolates from layer hens can harbor antibiotic resistance genes.
  • Plasmid-mediated quinolone resistance (PMQR) and β-lactamase genes are significant public health concerns.
  • Poultry can serve as a reservoir for resistant bacteria, potentially entering the food supply.

Purpose of the Study:

  • To investigate the presence and molecular characteristics of PMQR genes in β-lactamase-producing E. coli from layer hens.
  • To assess the transferability of resistance genes and the genetic relatedness of isolates.
  • To evaluate the potential of layer hens as a source of antibiotic-resistant bacteria in the food chain.

Main Methods:

  • Isolation and identification of E. coli from layer hens.
  • Antimicrobial susceptibility testing and detection of β-lactamase and PMQR genes (blaCTX-M-14, blaCMY-2, blaTEM-1, qnrS1, qnrB4).
  • Conjugation experiments to assess gene transferability and pulsed-field gel electrophoresis (PFGE) for molecular typing.

Main Results:

  • 60.6% of E. coli isolates were multidrug-resistant; 10.6% produced β-lactamase.
  • PMQR genes (qnrS1, qnrB4) were found in 6 of the 15 β-lactamase-producing isolates.
  • Transferability of resistance genes was observed in 33.3% of transconjugants; PFGE revealed three distinct patterns linked to resistance genes and farm origin.

Conclusions:

  • Layer hens can act as a reservoir for E. coli carrying both β-lactamase and PMQR genes.
  • The presence of transferable resistance genes poses a risk to the food chain.
  • Enhanced surveillance of antimicrobial use in poultry production is crucial to mitigate resistance spread.
Keywords:
Escherichia coliantimicrobial resistancelayer hensplasmid-mediated quinolone resistanceβ-lactamase

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