title: [Emergence of novel variants of gyrA, parC, qnrS genes in multi-drug resistant Klebsiella caused pneumonia].
abstract: OBJECTIVE
  To investigate the resistant mechanism of quinolones on multi-drug resistant Klebsiella caused pneumonia (MDR-KPN).
  
  
  METHODS
  From August 2008 to May 2010, 47 strains of MDR-KPN were collected from 6 hospitals in Hangzhou and Huzhou in Zhejiang province in China. Drug target genes to quinolones (gyrA, parC) and quinolone-resistance genes mediated by mobile genetic elements [qnrA, qnrB, qnrS, aac (6')-Ib-cr, qepA] were analyzed by PCR and verified by DNA sequencing.
  
  
  RESULTS
  Positive results were found in 47 strains of MDR-KPN, 43 strains (91.5%) of gyrA mutation, 40 strains (85.1%) of parC mutation, 3 strains (6.4%) of qnrB2, 1 strain (2.1%) of qnrB 4, 8 strains (17.0%) of qnrS 1, 5 strains (10.6%) of qnrS 4, 2 strains (4.3%) of aac (6')-Ib-cr respectively. Moreover, 5 novel variants of gyrA (GenBank accession number: JN811952, JN811953, JN811954, JN811955, JN811956), 5 novel variants of parC (GenBank accession number: JN817432, JN817433, JN817434, JN817435, JN817436) were also identified. In addition, qnrS4 (GenBank accession number: JN836269) appeared to be the novel variants of qnrS.
  
  
  CONCLUSIONS
  Quinolone-resistance-determining region played a key role on the resistance to quinolones in this group of MDR-KPN, and quinolone-resistance genes mediated by mobile genetic elements [qnrB2, qnrB4, qnrS1, qnrS4, aac (6')-Ib-cr] showed positive in some parts of the strains. This was the first report on emergence of qnrS4 in the world.
authors: Department of Microbiology Laboratory, Yuhang Hospital of Traditional Chinese Medicine, Hangzhou, China. zhujianming001@126.com
authors: Jian-ming
authors: JM
authors: Zhu
authors: Ru-jin
authors: RJ
authors: Jiang
authors: Hai-shen
authors: HS
authors: Kong
authors: Rong
authors: R
authors: Zhang
authors: Huo-xiang
authors: HX
authors: Lü
authors: Chang-gui
authors: CG
authors: Sun
authors: Zhi-mi
authors: ZM
authors: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D027081:DNA Gyrase / Q000235:genetics; D027101:DNA Topoisomerase IV / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005260:Female; D005798:Genes, Bacterial; D006801:Humans; D020071:Interspersed Repetitive Sequences; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D015363:Quinolones / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C485385:Qnr protein, Klebsiella pneumoniae; D015363:Quinolones; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase