摘要
Background： Klebsiellapneumoniae carbapenemase （KPC）-producing K. pneumoniae bacteria, which cause serious disease outbreaks worldwide, was rarely detected in Xiangya Hospital, prior to an outbreak that occurred from August 4, 2014, to March 17, 2015. The aim of this study was to analyze the epidemiology and molecular characteristics of the K. pneumoniae strains isolated during the outbreak. Methods： Nonduplicate carbapenem-resistant K. pneumoniae isolates were screened for blanc,＂ and multiple other resistance determinants using polymerase chain reaction. Subsequent studies included pulsed-field gel electrophoresis （PFGE）, multilocus sequence typing, analysis of plasmids, and genetic organization ofblaKPC-2 locus. Results： Seventeen blaKPC-2-positive K. pneumoniae were identified. A wide range of resistant determinants was detected. Most isolates （88.2%） coharbored blaKPC-2 and rmtB in addition to other resistance genes, including biaSHV-1, blaTEM-1, and aac（3）-lla. The blaKPC-2 and rmtB genes were located on the conjugative IncFIB-type plasmid. Genetic organization of blaKPC-2 locus in most strains was consistent with that of the plasmid pKP048. Four types （A l, A2, A3, and B） were detected by PFGE, and Type A1, an ST11, was the predominant PFGE type. A novel K. pneumoniae sequence type （ST1883） related to STI 1 was discovered. Conclusions： These isolates in our study appeared to be clonal and STI 1 K. pneumoniae was the predominant clone attributed to the outbreak. Coharbing of blaKPC-2 and rmtB, which were located on a transferable plasmid, in clinical K. pneumoniae isolates may lead to the emergence of a new pattern of drug resistance.
Background： Klebsiellapneumoniae carbapenemase （KPC）-producing K. pneumoniae bacteria, which cause serious disease outbreaks worldwide, was rarely detected in Xiangya Hospital, prior to an outbreak that occurred from August 4, 2014, to March 17, 2015. The aim of this study was to analyze the epidemiology and molecular characteristics of the K. pneumoniae strains isolated during the outbreak. Methods： Nonduplicate carbapenem-resistant K. pneumoniae isolates were screened for blanc,＂ and multiple other resistance determinants using polymerase chain reaction. Subsequent studies included pulsed-field gel electrophoresis （PFGE）, multilocus sequence typing, analysis of plasmids, and genetic organization ofblaKPC-2 locus. Results： Seventeen blaKPC-2-positive K. pneumoniae were identified. A wide range of resistant determinants was detected. Most isolates （88.2%） coharbored blaKPC-2 and rmtB in addition to other resistance genes, including biaSHV-1, blaTEM-1, and aac（3）-lla. The blaKPC-2 and rmtB genes were located on the conjugative IncFIB-type plasmid. Genetic organization of blaKPC-2 locus in most strains was consistent with that of the plasmid pKP048. Four types （A l, A2, A3, and B） were detected by PFGE, and Type A1, an ST11, was the predominant PFGE type. A novel K. pneumoniae sequence type （ST1883） related to STI 1 was discovered. Conclusions： These isolates in our study appeared to be clonal and STI 1 K. pneumoniae was the predominant clone attributed to the outbreak. Coharbing of blaKPC-2 and rmtB, which were located on a transferable plasmid, in clinical K. pneumoniae isolates may lead to the emergence of a new pattern of drug resistance.
基金
grants from Hunan Development and Reform Investment from the Development and Reform Commission of the Hunan Province，the Natural Science Foundation of the Hunan Province
