title: Novel variants of the qnrB gene, qnrB31 and qnrB32, in Klebsiella pneumoniae.
abstract: Quinolone resistance in the family Enterobacteriaceae is mostly attributed to the accumulation of mutations in the bacterial enzymes targeted by fluoroquinolones: DNA gyrase and DNA topoisomerase IV. Here we isolated the Klebsiella pneumoniae strains KP3606 and KP4707 from different specimens from 2008 to 2010 in Taizhou Municipal Hospital of China, and discovered a new subtype qnrB31, for which the GenBank accession number is HQ418999, and another new subtype qnrB32, for which the GenBank accession number is HQ704413. Susceptibility testing showed that KP3606 had a reduced susceptibility (MIC ≥0.5 µg ml(-1)) to quinolones, while KP4707 was resistant to quinolones. Of all qnrB alleles, the novel variants the qnrB32 gene and qnrB31 gene have the highest amino acid identity. The results suggested that of all the various genes involved in resistance to quinolones, the qnrB gene is the most likely to be mutated, and plasmids might play a role in the dissemination and evolution of qnrB genes.
authors.affiliation: Department of Clinical Laboratory Medicine, Medical College of Taizhou University Affiliated Taizhou Municipal Hospital, Taizhou, ZheJiang Province, PR China.
authors.forename: Dongguo
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory Medicine, Medical College of Taizhou University Affiliated Taizhou Municipal Hospital, Taizhou, ZheJiang Province, PR China.
authors.forename: Haibao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, Medical College of Taizhou University, Taizhou, ZheJiang Province, PR China.
authors.forename: Yongxiao
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Department of Laboratory Medicine, Medical College of Taizhou University, Taizhou, ZheJiang Province, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Clinical Laboratory Medicine, Medical College of Taizhou University Affiliated Taizhou Municipal Hospital, Taizhou, ZheJiang Province, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Clinical Laboratory Medicine, Medical College of Taizhou University Affiliated Taizhou Municipal Hospital, Taizhou, ZheJiang Province, PR China.
authors.forename: Lianhua
authors.initials: L
authors.lastname: Yu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D027081:DNA Gyrase / Q000235:genetics; D027101:DNA Topoisomerase IV / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D014644:Genetic Variation; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D015363:Quinolones / Q000494:pharmacology*; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D015363:Quinolones; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase