title: Detection of plasmid-mediated quinolone resistance determinants and qnrS expression in Enterobacteriaceae clinical isolates.
abstract: BACKGROUND
  Rapid dissemination of plasmid-mediated quinolone resistance (PMQR) has been reported in clinical isolates.
  
  
  METHODS
  A total of 149 clinical isolates of Enterobacteriaceae were collected in Beijing and screened for PMQR genes using polymerase chain reaction (PCR). Real-time quantitative PCR was used to study the expression of qnrS.
  
  
  RESULTS
  The rates of qnr and aac(6')-Ib-cr genes were 7.4% and 8.1%, respectively. The higher basal expression of qnrS was observed in transconjugant strains, which had higher minimum inhibitory concentrations (MICs) of quinolones. Furthermore, qnrS expression levels increased in all three isolates when a quinolone was present.
  
  
  CONCLUSIONS
  Our data suggest that the level of qnrS expression was associated with quinolone resistance.
authors.affiliation: College of Life Sciences, Henan Normal University, Xinxiang, China. jxb841001@163.com.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Jiang
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Yunshan
authors.initials: Y
authors.lastname: Zhang
authors.forename: He
authors.initials: H
authors.lastname: Yan
authors.forename: Yuxiao
authors.initials: Y
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.forename: Lijun
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002681:China; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D020869:Gene Expression Profiling; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000032:analysis*; D016133:Polymerase Chain Reaction; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D015363:Quinolones