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An insight into selection specificity of quinolone resistance determinants within Enterobacteriaceae family

Nivedita Dasgupta1, Deepjyoti Paul1, Debadatta Dhar Chanda2

  • 1Department of Microbiology, Assam University, Silchar, Assam, India.

Journal of Global Antimicrobial Resistance
|June 17, 2017
PubMed
Abstract

Insights

Quinolone resistance genes like qnr and aac(6')-Ib-cr are prevalent in Enterobacteriaceae. Their presence increases quinolone resistance, potentially causing treatment failure.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Antimicrobial Resistance

Background:

  • Quinolone antimicrobials are prone to misuse, leading to resistance and treatment failure.
  • Plasmid-mediated quinolone resistance (PMQR) determinants contribute significantly to this issue.
  • Enterobacteriaceae are common pathogens where quinolone resistance is a growing concern.

Purpose of the Study:

  • To characterize plasmid-mediated quinolone resistance (PMQR) determinants in Enterobacteriaceae.
  • To investigate the genetic selection of these resistance mechanisms under quinolone stress.
  • To understand the prevalence and transferability of key resistance genes.

Main Methods:

  • Collected 209 Enterobacteriaceae isolates from healthcare facilities.
  • Performed molecular characterization using multiplex PCR.
  • Utilized transformation assays with specific quinolones to select for resistance genes (qnrA, qnrB, qnrD, qnrS, aac(6 extprime)-Ib-cr) in Escherichia coli DH5α.
  • Conducted conjugation experiments to assess plasmid transferability.

Main Results:

  • Specific qnr genes and aac(6 extprime)-Ib-cr were successfully selected using different quinolones (norfloxacin, ciprofloxacin, ofloxacin, levofloxacin).
  • qnrA, qnrB, qnrD, qnrS, and aac(6 extprime)-Ib-cr exhibited differential selection based on the quinolone used.
  • The study demonstrated the presence and selection of key PMQR determinants within Enterobacteriaceae.

Conclusions:

  • The presence of qnr genes correlates with increased quinolone minimum inhibitory concentrations (MICs).
  • PMQR determinants are prevalent and can lead to treatment failures.
  • Effective surveillance and control measures are crucial to combat quinolone resistance.
Keywords:
Antimicrobial usePlasmid-mediated antimicrobial resistanceQuinolone resistanceResistance gene

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