title: Detection and genotype analysis of AmpC β-lactamase inKlebsiella pneumoniaefrom tertiary hospitals.
abstract: The aim of the present study was to investigate the phenotype and genotype of plasmid-mediated AmpC (pAmpC) β-lactamase inKlebsiella pneumoniaeand its antibiotic resistance. A total of 130 non-repetitive clinical isolates ofKlebsiella pneumoniae, obtained from tertiary hospitals, were phenotypically screened for pAmpC β-lactamase production with the cefoxitin disk diffusion test. β-lactamase genes in the screened isolates were detected using multiplex polymerase chain reaction (PCR); carbapenemase genes in pAmpC β-lactamase-producing isolates that were resistant to imipenem were detected using PCR. Out of the 130 isolates ofKlebsiella pneumoniae, 62 strains (47.7%) were resistant to cefoxitin, including 14 strains (10.8%) positive for pAmpC β-lactamase (DHA type), among which 12 strains (85.7%) were susceptible to imipenem, and 2 strains, which were carryingKlebsiella pneumoniaecarbapenemase (KPC)-2 gene, were resistant to imipenem. The pAmpC β-lactamase-producingKlebsiella pneumoniaeisolates from the tertiary hospitals were mainly of DHA-1 genotype, and the majority were susceptible to carbapenems; drug-resistant strains were associated with KPC-2 expression.
authors.affiliation: Department of Pneumology, Xuzhou City Hospital Affiliated to Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China.
authors.forename: Xiang-Qun
authors.initials: XQ
authors.lastname: Liu
authors.affiliation: Department of Pneumology, Xuzhou City Hospital Affiliated to Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China.
authors.forename: Yong-Rui
authors.initials: YR
authors.lastname: Liu
keywords: AmpC β-lactamase; Klebsiella pneumoniae; carbapenemase; plasmid