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Increased prevalence of plasmid-mediated quinolone resistance determinants in chicken Escherichia coli isolates from

Si-Yang Huang1, Lei Dai, Li-Ning Xia

  • 1National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China.

Foodborne Pathogens and Disease
|September 9, 2009
PubMed

Insights

Plasmid-mediated quinolone resistance (PMQR) determinants in chicken E. coli increased significantly from 2001 to 2007 in China. This rise in resistance genes, like qnr and aac(6)-Ib-cr, correlates with increased ciprofloxacin resistance, posing a threat to public health.

Area of Science:

  • Veterinary Microbiology
  • Antimicrobial Resistance
  • Molecular Epidemiology

Background:

  • Plasmid-mediated quinolone resistance (PMQR) determinants are a growing concern in food-producing animals.
  • Understanding the temporal dynamics of PMQR in poultry is crucial for monitoring resistance trends.

Purpose of the Study:

  • To evaluate the temporal changes in PMQR determinants in chicken Escherichia coli isolates between 2001 and 2007.
  • To investigate the association between PMQR prevalence and ciprofloxacin resistance.

Main Methods:

  • Screening of 532 chicken E. coli isolates for PMQR determinants using PCR and sequencing.
  • Analysis of gene prevalence, including qnr genes, aac(6')-Ib-cr, and qepA.
  • Pulsed-field gel electrophoresis and plasmid analysis to assess genetic diversity and transferability.

Main Results:

  • Prevalence of qnr genes, aac(6')-Ib-cr, and qepA were 9.8%, 11.7%, and 0.75%, respectively.
  • Significant increase in ciprofloxacin resistance and PMQR gene prevalence from 2001 to 2007 (p < 0.01).
  • PMQR determinants were transferable via conjugation and located on diverse plasmids.

Conclusions:

  • PMQR determinants are highly prevalent and increasing in chicken E. coli in China.
  • Horizontal gene transfer and quinolone use likely drive PMQR spread in poultry.
  • Widespread PMQR dissemination may accelerate fluoroquinolone resistance development.

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