Detection of the qnr gene responsible for plasmid-mediated quinolone resistance / 中国感染与化疗杂志

ABSTRACT

Objective To explore the prevalence of qnr gene in gram-negative bacteria isolated from Renmin Hospital of Wuhan University. Methods qnr gene was detected by PCR in non-duplicate E.coli (n=129), E.cloacae (n=10) and K.pneumoniae (n=29) isolates.PCR technique was used to amplify the gene encoding type I integrons.Kirby-Bauer disk diffusion method was used to test the in vitro suscepti- bility of the isolates to 16 antimicrobial agents.ESBLs were investigated according to phenotypie screening and confirmatory test recom- mended by NCCLS.MIC values of ciprofloxacin were determined for qnr gene positive strains.Results qnr gene were identified in 6 clinical isolates including 5 strains of E.coli and I E.cloacae, qnr gene was not found in K.pneumoniae isolates.The 6 qnr-positive clinical iso- lates were positive for type I integrons.All the 6 strains were susceptible to imipenem but resistant to many other drugs tested.Only 2 of the E.coli isolates were susceptible to ciprofloxacin.Conclusions In Hubei Province, the prevalence of qnr is confirmed.The serious situa- tion of multidrug-resistance in clinical isolates with qnr gene requires careful monitoring of qnr-carrying isolates.