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Fecal colonization of Enterobacteriaceae carrying plasmid-mediated quinolone resistance determinants in Korea

Haeng Soon Jeong1, Il Kwon Bae, Jeong Hwan Shin

  • 1Department of Laboratory Medicine, Inje University College of Medicine, 633-165 Gaegeum-dong Busanjin-gu, Busan, Korea.

Microbial Drug Resistance (Larchmont, N.Y.)
|August 12, 2011
PubMed

Insights

Plasmid-mediated quinolone resistance (PMQR) genes are prevalent in fecal Enterobacteriaceae in Korea. The study found a high incidence of qnrB and aac(6')-Ib-cr genes, with several novel variants identified.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Infectious Diseases

Background:

  • Plasmid-mediated quinolone resistance (PMQR) genes contribute to antimicrobial resistance.
  • Understanding the prevalence and molecular characteristics of PMQR genes is crucial for public health.
  • Enterobacteriaceae are common causes of infections and can harbor resistance genes.

Purpose of the Study:

  • To investigate the prevalence and molecular characteristics of PMQR genes in fecal Enterobacteriaceae.
  • To compare the incidence and subtypes of PMQR genes across different bacterial species and hospitals.
  • To identify novel variants of PMQR genes.

Main Methods:

  • Collected 500 nonduplicated Enterobacteriaceae isolates from fecal specimens at five Korean tertiary-care hospitals.
  • Utilized Polymerase Chain Reaction (PCR) to amplify and direct sequencing to confirm PMQR genes (qnrA, qnrB, qnrS, aac(6 ext{ extquotesingle}) -Ib-cr, and qepA).
  • Analyzed gene prevalence, distribution by species and hospital, and identified gene subtypes and variants.

Main Results:

  • 83 (16.6%) of isolates were qnr-positive, with qnrB being the most prevalent (13.6%).
  • High prevalence of qnrB was observed in Klebsiella pneumoniae (33.9%) and Citrobacter braakii (61.5%).
  • aac(6 ext{ extquotesingle}) -Ib-cr was detected in 15.6% of isolates, often co-occurring with qnr genes. Seven novel qnrB variants and one qepA variant were identified.

Conclusions:

  • PMQR genes are highly prevalent in Enterobacteriaceae from stool specimens in Korea.
  • A significant association exists between qnr and aac(6 ext{ extquotesingle}) -Ib-cr genes.
  • The emergence of novel PMQR gene variants highlights the need for continuous surveillance.

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