title: Occurrence of qnr-positive clinical isolates in Klebsiella pneumoniae producing ESBL or AmpC-type beta-lactamase from five pediatric hospitals in China.
abstract: The plasmid-mediated quinolone resistance qnr genes in clinical isolates in adults have been described in different countries; however, the frequency of their occurrence has not been detected in pediatric patients. A total of 410 clinical isolates of Klebsiella pneumoniae, identified as producers of an extended-spectrum beta-lactamase (ESBL), or AmpC beta-lactamase, were collected from five children's hospitals in China during 2005-2006. The isolates were screened for the presence of the qnrA, qnrB, and qnrS genes, and then the harboring qnr gene isolates were detected for a bla gene coding for the TEM, SHV, CTX-M, and plasmid-mediated ampC gene by a PCR experiment. Ninety-two isolates (22.7%) were positive for the qnr gene, including 10 of qnrA (2.4%), 25 of qnrB (6.1%), and 62 of qnrS (15.1%). Eighty-one of the 92 (88.0%) qnr-positive isolates carried at least one bla gene for TEM, SHV, CTX-M, or DHA-1. The ciprofloxacin resistance increased 16-256-fold and oflaxacin resistance increased 2-32-fold in transconjugants, respectively. These results indicated that the plasmid-mediated qnr quinolone resistance gene was qnrS, followed by qnrB and qnrA. Most of the isolates also carried a bla gene coding ESBL or ampC gene coding DHA-1 among Klebsiella pneumoniae isolated from Chinese pediatric patients.
authors.affiliation: Beijing Children's Hospital, Capital Medical University, Beijing, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Wang
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Yang
authors.forename: Quan
authors.initials: Q
authors.lastname: Lu
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Deng
authors.forename: Hui
authors.initials: H
authors.lastname: Ding
authors.forename: Qiulian
authors.initials: Q
authors.lastname: Deng
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Xuzhuang
authors.initials: X
authors.lastname: Shen
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002681:China; D002939:Ciprofloxacin / Q000378:metabolism; D003227:Conjugation, Genetic; D003428:Cross Infection / Q000235:genetics; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007710:Klebsiella Infections / Q000235:genetics*; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D015242:Ofloxacin / Q000378:metabolism; D010957:Plasmids; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C485385:Qnr protein, Klebsiella pneumoniae; D002939:Ciprofloxacin; D015242:Ofloxacin; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; C492230:beta-lactamase CTM-X-23, Klebsiella pneumoniae; C519492:beta-lactamase SHV-31, Klebsiella pneumoniae; C477298:beta-lactamase TEM-102, Klebsiella pneumoniae