| Summary: | Nagasaki University (長崎大学) 博士(医学) This study investigated the molecular and phenotypic characteristics of carbapenemase-producing Klebsiella pneumoniae, and identified the risk factors underlying its acquisition. We evaluated K. pneumoniae isolated in Nagasaki University Hospital between January 2009 and June 2015. The presence of carbapenemase genes and plasmid characteristics were investigated. We performed multilocus sequence typing (MLST), and generated a dendrogram based on the results of pulsed-field gel electrophoresis (PFGE) for carbapenemase-producing strains. We also performed a case-control study of patients. Of the 88 K. pneumoniae strains that showed minimum inhibitory concentration ?1 μg/mL for imipenem and/or meropenem, and that were available from our bacterial collection, 18 had the IMP-type carbapenemase gene, all of which were IMP-1 according to sequencing analysis. Strains included seven different sequence types (STs), of which the most common was ST1471. A dendrogram showed the significant similarity of some strains with relationships in PFGE patterns, STs, and the wards in which they were isolated. Plasmid incompatibility group was similar among the IMP-1 producers. Regarding risk factors, multivariate analysis showed that liver disease and previous uses of carbapenems and anti-fungal drugs were significant factors for the acquisition of IMP-1-producing strains. Our results demonstrate that IMP-1 is a major carbapenemase produced by K. pneumoniae. The PFGE results indicated the possibility of transmission in the hospital. The identified risk factors should be considered for appropriate antibiotic therapy and infection-control measures. 長崎大学学位論文 学位記番号:博(医歯薬)甲第1120号 学位授与年月日:平成31年3月6日 Author: Hiromi Yamakawa, Kosuke Kosai, Norihiko Akamatsu, Junichi Matsuda, Norihito Kaku, Naoki Uno, Yoshitomo Morinaga, Hiroo Hasegawa, Taishi Tsubouchi, Yukihiro Kaneko, Taiga Miyazaki, Koichi Izumikawa, Hiroshi Mukae, Katsunori Yanagihara Citation: Journal of Infection and Chemotherapy, 25(4), ...
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