Prevalence and molecular characterization of carbapenemase-producing gram-negative bacteria from a university hospital in China

作者：Yao Sun, Meimei Li, Lijiang Chen, Huale Chen, Xiao Yu, Jianzhong Ye, Yapei Zhang, Chuanling Ma, Tieli Zhou · 发表于：Scandinavian Journal of Infectious Diseases · 年份：2015 · DOI：10.3109/23744235.2015.1094822 · 被引用次数：18 · 研究领域：Antibiotic Resistance in Bacteria、Infections and bacterial resistance、Antibiotics Pharmacokinetics and Efficacy

BACKGROUND: The increasing emergence of carbapenem resistance in gram-negative bacteria associated with carbapenemase prompted the initiation of this study. METHODS: A total of 3139 gram-negative bacteria were recovered from a 3380-bed university hospital in Wenzhou during 2008 and 2012. Antimicrobial susceptibility was determined using the VITEK2 Compact System and agar dilution method. The phenotype and genotype of carbapenemase were demonstrated using the modified Hodge test, PCR and sequencing. A conjugation experiment was performed to reveal the transferability of resistant genes. The location of the carbapenemase gene was studied by plasmid analysis and southern blot hybridization. Clonal relatedness of the isolates was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). RESULTS: Overall, 751 of 3139 isolates (71/2055 Enterobacteriaceae, 510/620 Acinetobacter baumannii and 170/464 Pseudomonas aeruginosa) exhibited resistance to carbapenem. Carbapenemase-encoding genes were detected in 70.4% (50/71) of carbapenem-resistant Enterobacteriaceae, including blaKPC (80%) and blaIMP (20%). All A. baumannii subjected to genotype analysis were positive for blaOXA-51-like and co-harboured blaOXA-23-like (80.4%) and blaIMP (7.8%). ISAba1 was found upstream of blaOXA-23-like and blaOXA-51-like. Eight and seven strains of 170 P. aeruginosa carried blaIMP and blaVIM, respectively. PFGE analysis identified at least one dominant genotype in cer...