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: Shuchang An, Jichao Chen, Zhanwei Wang, Xiaorong Wang, Xixin Yan, Jihong Li, Yusheng Chen, Qi Wang, Xiaoling Xu, Jiabin Li, Jingping Yang, Hui Wang, Zhancheng Gao
• Journal: FEMS microbiology letters (FEMS Microbiol Lett) Vol. 332 Issue 2 Pg. 137-45 (Jul 2012) ISSN: 1574-6968 [Electronic] England
• PMID: 22537112 (Publication Type: Letter, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Chemical References

• Anti-Bacterial Agents
• DNA, Bacterial
• beta-Lactams
• beta-Lactamases

Topics

• Anti-Bacterial Agents (pharmacology)
• China
• DNA, Bacterial (chemistry, genetics)
• Humans
• Klebsiella Infections (microbiology)
• Klebsiella pneumoniae (classification, enzymology, genetics, isolation & purification)
• Microbial Sensitivity Tests
• Molecular Sequence Data
• Multilocus Sequence Typing
• Respiratory Tract Infections (microbiology)
• Sequence Analysis, DNA
• beta-Lactamases (metabolism)
• beta-Lactams (pharmacology)