北部某區域醫院克雷伯氏肺炎桿菌碳青黴烯酶之分子流行病學分析

Molecular Epidemiology Analysis of Klebsiella Pneumoniae Carbapenemase in Regional Hospital of North Taiwan

抗藥性基因可在不同的菌屬間傳播，常造成院內感控議題，亦可能會導致全球公共衛生問題，故監測抗藥性基因盛行率已成臨床工作一個重要課題。KPC （Klebsiella pneumoniae carbapenemase）是腸內菌常見的抗藥性基因，因此，我們收集CRE（Carbapenem-resistant Enterobacteriaceae）進行全院抗藥性細菌監測，以了解CRE攜帶blaKPC的流行現況及抗藥菌株間的親緣性關係。病人分離菌株經由改良賀治試驗（Modified Hodge test）檢測此菌種對carbapenem類抗生素之水解能力，並以聚合酶連鎖反應（Polymerase chain reaction）觀察blaKPC表現，最後利用脈衝式凝膠電泳（Pulse-filed gelelectrophoresis）分析帶有抗藥性基因菌株，以釐清菌株間關聯性。本研究共分析211株自病人分離菌株，並對imipenem、ertapenem或meropenem其中一種呈抗性腸內菌，收集時間自2011年8月至2015年7月，分離菌株主要為Klebsiella pneumoniae（n=121），其次為Escherichia coli（n=25）、Morganella morganii（n=19）及其他腸內菌（n=46）。在211株中有24株（11.4%）改良賀治試驗呈現陽性，12株攜帶blaKPC （5.7%），帶有blaKPC之中11株為K. pneumoniae，另1株為E. coli。我們進一步探討攜帶blaKPC之K. pneumoniae親緣關係，發現90.9%為同一個基因型（pulsotype），顯示此11株K.pneumoniae具有高度親緣性。此外，我們也發現有12株經改良賀治試驗呈陽性，但blaKPC表現呈陰性，說明可能是其他抗藥性基因或機轉造成抗藥性。本研究顯示CRE攜帶blaKPC是以K. pneumoniae為主要菌株，且具有高度親緣相關性，為避免CRE造成院內散播及群聚感染，應更加強和落實感染管制措施。 Resistance of bacteria to antibiotics is mainly associated with acquired resistance genes. The genescan spread across strains, which may result in global health issues. Therefore, monitoringprevalence of resistance genes becomes an important task in clinical workplace. KPC (Klebsiellaepneumoniae carbapenemase) is the common resistance gene in Enterobacteriaceae. For this reason,we collected CRE (Carbapenem-resistant Enterobacteriaceae) to monitor antibiotic resistant strainsat En Chu Kong hospital, to understand the prevalence of blaKPC-carrying CRE and the geneticrelationship between strains. The production of carbapenemase was detected by the modifiedHodge test (MHT), and the blaKPC expression was observed by polymerase chain reaction (PCR).The relationships between isolated strains were analyzed by pulse-filed gel electrophoresis (PFGE).From August 2011 to July 2015, 211 strains of carbapenem-resistant to one of imipenem,meropenem and ertapenem were isolated and analyzed. The most common species were Klebsiellapneumoniae (n=121), followed by Escherichia coli (n=25), Morganella morganii (n=19), and otherspecies (n=46). Of which, twenty-four (11.4 %) isolates showed carbapenemase activity, and twelve(5.7 %) isolates contained blaKPC including eleven K. pneumoniae and one E. coli. PFGE analysisfound 90.9% belonging to same pulsotype for blaKPC-carrying K. pneumoniae isolates that displayedhigh level correlation of antibiotic resistant strains. In addition, we also found twelve isolates werepositive to MHT but blaKPC showed negative from PCR. Those results indicated carbapenemasewas possibly produced with other KPC subtype or resistant mechanism. This study revealed CREwith blaKPC was mainly in K. pneumoniae with high level phylogenetic relationship. To avoid thenosocomial transmission and cluster infection, we should further strengthen and implementinfection control measures.

Resistance of bacteria to antibiotics is mainly associated with acquired resistance genes. The genescan spread across strains, which may result in global health issues. Therefore, monitoringprevalence of resistance genes becomes an important task in clinical workplace. KPC (Klebsiellaepneumoniae carbapenemase) is the common resistance gene in Enterobacteriaceae. For this reason,we collected CRE (Carbapenem-resistant Enterobacteriaceae) to monitor antibiotic resistant strainsat En Chu Kong hospital, to understand the prevalence of blaKPC-carrying CRE and the geneticrelationship between strains. The production of carbapenemase was detected by the modifiedHodge test (MHT), and the blaKPC expression was observed by polymerase chain reaction (PCR).The relationships between isolated strains were analyzed by pulse-filed gel electrophoresis (PFGE).From August 2011 to July 2015, 211 strains of carbapenem-resistant to one of imipenem,meropenem and ertapenem were isolated and analyzed. The most common species were Klebsiellapneumoniae (n=121), followed by Escherichia coli (n=25), Morganella morganii (n=19), and otherspecies (n=46). Of which, twenty-four (11.4 %) isolates showed carbapenemase activity, and twelve(5.7 %) isolates contained blaKPC including eleven K. pneumoniae and one E. coli. PFGE analysisfound 90.9% belonging to same pulsotype for blaKPC-carrying K. pneumoniae isolates that displayedhigh level correlation of antibiotic resistant strains. In addition, we also found twelve isolates werepositive to MHT but blaKPC showed negative from PCR. Those results indicated carbapenemasewas possibly produced with other KPC subtype or resistant mechanism. This study revealed CREwith blaKPC was mainly in K. pneumoniae with high level phylogenetic relationship. To avoid thenosocomial transmission and cluster infection, we should further strengthen and implementinfection control measures.