Accumulation of plasmid-mediated fluoroquinolone resistance genes, qepA and qnrSl, in Enterobacter aerogenes co-producing RmtB and class A β-lactamase LAP-1

Yeon Joon Park, Jin Kyung Yu, Sang Il Kim, Kyungwon Lee, Yoshichika Arakawa

Research output: Contribution to journalArticle

28 Citations (Scopus)


A new plasmid-mediated fluoroquinolone efflux pump gene, qepA, is known to be associated with the rmtB gene, which confers high-level resistance to aminoglycosides. We investigated the qepA gene in 573 AmpC-producing Enterobacteriaceae including one Citrobacter freundii known to harbor rmtB. Of them, two clonally unrelated E. aerogenes harbored qepA. Both isolates co-harbored rmtB, qnrS1, qepA, and blaLAP-1 on an IncFI type plasmid. The qepA was flanked by two copies of IS26 containing ISCR3C, tnpA, tnpR, blaTEM, and rmtB. The qnrS1 and blaLAP-1 were located upstream of qepA. All the resistance determinants (qepA, qnrS1, rmtB, and blaLAP-1) were co-transferred to E. coli J53 by filter mating from both isolates. Although the prevalence of qepA is currently low, considering the presence of ISCR3C and the possibility of co-selection and co-transferability of plasmids, more active surveillance for these multi-drug resistant bacteria and prudent use of antimicrobials are needed.

Original languageEnglish
Pages (from-to)55-59
Number of pages5
JournalAnnals of Clinical and Laboratory Science
Issue number1
Publication statusPublished - 2009 Jan 1


All Science Journal Classification (ASJC) codes

  • Microbiology
  • Immunology and Allergy
  • Pathology and Forensic Medicine
  • Immunology
  • Molecular Biology
  • Hematology
  • Clinical Biochemistry
  • Medical Laboratory Technology

Cite this