title: Prevalence of plasmid-mediated quinolone resistance genes and ciprofloxacin resistance in pediatric bloodstream isolates of Enterobacteriaceae over a 9-year period.
abstract: A total of 279 isolates of Escherichia coli (n = 128) and Klebsiella pneumoniae (n = 151) were obtained from blood samples from children at the Seoul National University Children's Hospital, Seoul, Korea from 1999 to 2007. Five plasmid-mediated quinolone resistance (PMQR) genes, qnrA, qnrB, qnrS, qepA, and aac(6')-Ib-cr, and the minimal inhibitory concentration (MIC) values for ciprofloxacin were tested for all the strains. Mutations in both gyrA and parC were analyzed in 57 representative strains. Twenty-seven strains (9.7%) had at least 1 of the 5 PMQR genes: qnrB in 20 isolates, qnrS in 1, aac(6')-Ib-cr in 5, and both qnrB and aac(6')-Ib-cr in 1 isolate. The overall PMQR prevalence rates tended to increase over time (P = 0.001). The non-susceptibility rate to ciprofloxacin was 11.0% (31/279). PMQR-harboring isolates tended to have increased ciprofloxacin MIC values among both quinolone resistance-determining region (QRDR) mutation-present (P = 0.016) and QRDR mutation-absent isolates (P < 0.001). The increasing prevalence of PMQR genes was associated with increase in quinolone use over time (P < 0.001) and increasing frequency of non-susceptibility to ciprofloxacin (P < 0.001).
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Nam Hee
authors.initials: NH
authors.lastname: Kim
authors.forename: Eun Hwa
authors.initials: EH
authors.lastname: Choi
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Sung
authors.forename: Chi Eun
authors.initials: CE
authors.lastname: Oh
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Kim
authors.forename: Eui-Chong
authors.initials: EC
authors.lastname: Kim
authors.forename: Hoan Jong
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D015363:Quinolones / Q000494:pharmacology*; D056910:Republic of Korea / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D015363:Quinolones