title: Prevalence of plasmid-mediated qnr determinants and gyrase alteration in Klebsiella pneumoniae isolated from a university teaching hospital in Malaysia.
abstract: OBJECTIVE
  The ciprofloxacin resistance of Klebsiella (K.) pneumoniae is mediated primarily through alterations in type II topoisomerase (gyrA) gene and plasmid-mediated quinolone resistance-conferring genes (qnr). This study aimed to define the prevalence of plasmid-mediated quinolone resistance-conferring genes (qnr) and type II topoisomerase (gyrA) alterations of a population of ciprofloxacin-resistant (n = 21), intermediate (n = 8), and sensitive (n = 18) K. pneumoniae isolates obtained from a teaching hospital at Kuala Lumpur, Malaysia.
  
  
  METHODS
  A multiplex PCR assay was performed for simultaneous detection of qnrA, qnrB and qnrS. Sequence analysis of the amplified gyrA and gyrB regions of the isolates were performed.
  
  
  RESULTS
  The findings in this study revealed the emergence of a high prevalence (48.9%) of qnr determinants in our isolates. Four variants of plasmid-mediated qnr determinants (qnrB1, qnrB6, qnrB10 and qnrS1) were detected from 11 (52.4%) ciprofloxacin-resistant, 5 (62.5%) intermediate and 7 (38.9%) sensitive isolates. gyrA alterations were detected from 18 (85.7%) ciprofloxacin-resistant isolates. Single gyrA alterations, Ser83→Tyr, Ser83→Ile, and Asp87→Gly, and double alterations, Ser83→Phe plus Asp87→Ala and Ser83→Tyr plus Asp87→Asn were detected. While ciprofloxacin resistance was significantly associated with gyrA alteration (Ser83, p = 0.003; Asp87, p = 0.005; double alteration, p = 0.016), no significant association of ciprofloxacin resistance was noted with the presence of qnr determinants (p = 0.283).
  
  
  CONCLUSIONS
  The findings in this study demonstrate the emergence of qnr determinants and gyrA alterations contributed to the development and spread of fluoroquinolone resistance in the Malaysian isolates.
authors.affiliation: Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: A S
authors.initials: AS
authors.lastname: Saiful Anuar
authors.forename: M Y
authors.initials: MY
authors.lastname: Mohd Yusof
authors.forename: S T
authors.initials: ST
authors.lastname: Tay
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D002939:Ciprofloxacin / Q000494:pharmacology; D003428:Cross Infection / Q000382:microbiology; D027081:DNA Gyrase / Q000235:genetics*; D024881:Drug Resistance, Bacterial; D006784:Hospitals, Teaching; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics*; D008296:Malaysia; D010957:Plasmids / Q000235:genetics*; D016133:Polymerase Chain Reaction
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C485385:Qnr protein, Klebsiella pneumoniae; D002939:Ciprofloxacin; D027081:DNA Gyrase