title: Predominant characteristics of CTX-M-producing Klebsiella pneumoniae isolates from patients with lower respiratory tract infection in multiple medical centers in China.
abstract: From February 2010 to July 2011, 183 of 416 presumptive Klebsiella pneumoniae isolates with reduced susceptibility to third-generation cephalosporins from patients with lower respiratory tract infection were collected from seven tertiary hospitals in China. Phenotypic and genotypic methods were employed to characterize 158 extended-spectrum β-lactamase (ESBL)-producers. Among the 158 isolates analyzed, 134 (84.8%) harbored bla(CTX-M) , within which the most predominant ESBL gene was CTX-M-14 (49.4%), followed by CTX-M-15 (12.0%) and CTX-M-27 (10.8%). Also, 120 (75.9%) harbored bla(SHV) . One novel SHV variant, bla(SHV -142) with T18A and L35Q substitutions, was identified. Ninety-one isolates carried bla(TEM-1). An isolate containing bla(TEM-135) was first identified in Klebsiella spp. bla(KPC)-2) was detected in 5 isolates. More than one ESBL combination was detected in 18 isolates (11.4%). Fifty-four (34.2%) isolates demonstrated the multidrug resistant (MDR) phenotype. Seventy-four sequence types (STs) were identified, which showed large genetic background diversity in ESBL-producing K. pneumoniae isolates from the six areas. This is the first report on the high prevalence of CTX-M-27 in China with the possible transmission of a single clone (ST48). The correlated surveillance of organisms with MDR phenotype should be investigated in future.
authors.affiliation: Department of Respiratory and Critical Care Medicine, Peking University People's Hospital, Beijing, China.
authors.forename: Shuchang
authors.initials: S
authors.lastname: An
authors.forename: Jichao
authors.initials: J
authors.lastname: Chen
authors.forename: Zhanwei
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Wang
authors.forename: Xixin
authors.initials: X
authors.lastname: Yan
authors.forename: Jihong
authors.initials: J
authors.lastname: Li
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Chen
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Xu
authors.forename: Jiabin
authors.initials: J
authors.lastname: Li
authors.forename: Jingping
authors.initials: J
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Zhancheng
authors.initials: Z
authors.lastname: Gao
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D012141:Respiratory Tract Infections / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000378:metabolism*; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases