【摘要】 目的了解某院重症监护室(ICU)分离的多重耐药鲍曼不动杆菌(MDR-AB)Ⅰ型整合子阳性率,并分析MDR-AB的同源性,探讨Ⅰ型整合子参与耐药、传播的分子机制。方法收集2008年1月—2009年12月该ICU分离的40株MDR-AB,采用K-B纸片扩散法检测其耐药性,聚合酶链反应(PCR)进行Ⅰ类整合子可变区扩增、克隆测序,分析Ⅰ类整合子基因结构。应用脉冲场凝胶电泳(PFGE)分析MDR-AB的同源性。结果 75.00%(30/40)的菌株Ⅰ类整合子阳性,共检测出两种基因盒,分别为aacA4-catB8-aadA1和aacC1-orfX-orfX-orfX’-aad A1。PF-GE结果表明,40株菌分为4个克隆,其中有26株属于B克隆,为主要流行菌株型。结论Ⅰ类整合子在MDR-AB中广泛存在,可能通过水平传播方式在ICU中传播。携带aacA4-catB8-aadA1整合子的MDR-AB引起了ICU鲍曼不动杆菌的流行。更多还原

【Abstract】 Objective To investigate the positive rate of class Ⅰintegron in Acinetobacter baumannii(AB) isolated from an intensive care unit(ICU),analyze the homology of multidrug-resistant AB(MDR-AB),and explore the molecular mechanisms of class I integron involved in drug resistance and the spread.Methods Forty MDR-AB isolates from the ICU between January 2008 and December 2009 were collected,drug resistance of all isolates were detected by Kirby-Bauer method,PCR and DNA sequencing were undertaken to clarify the context of gene cassette.Pulsed-field gel electrophoresis was used to analyze the homology of MDR-AB.Results ClassⅠintegron was detected in 75.00%(30/40) of all isolates,2 types of gene cassettes were identified,namely aacA4-catB8-aadA1 and aacC1-orfX-orfX-orfX’-aadA1.Forty isolates were classified into 4 distinct genotypes by PFGE analysis,26 isolates belonged to clone B that were predominant epidemic strain.Conclusion class Ⅰintegrons are widespread in MDR-AB,and spread horizontally in ICU.The epidemic of AB in ICU maybe caused by MDR-AB carrying aacA4-catB8-aadA1 cassette.更多还原