摘要
目的探讨复旦大学附属中山医院耐碳青霉烯酶鲍氏不动杆菌(CRAB)之间的同源性,了解有无流行暴发以及流行变迁。方法对医院2007-2008年以及2005年上半年下呼吸道标本分离的CRAB复活后采用脉冲场凝胶电泳(PFGE)方法进行基因分型,分析同源性。结果 PFGE方法分析发现,2007-2008年所复活的63株细菌中共有A、C-L等11种基因型,主要为流行株C和流行株E,各有20株,各占31.7%;此时期,外科重症监护病房(SICU)分离的25株CRAB主要来源于流行株C(72.0%),该病区中流行株C最早分离于2007年12月,之后在2008年引起持续而频繁的感染;急诊重症监护病房(EICU)分离的细菌以流行株G1为主(40.0%),呼吸科病房及留院观察室均以克隆株E为主;SICU 2005年2-6月分离的CRAB有A和B两种基因型,以流行株B为主,占80.0%;克隆株A首次分离于2005年2月的SICU的痰标本,之后(2007-2008年)在所研究的各个病区间断出现。结论近两年医院CRAB主要的PFGE基因型为流行株C和流行株E,克隆株G1和克隆株E可引起暴发流行;同一克隆株可在同一病房内发生交叉感染从而引起流行暴发;流行相关的克隆株可在病区长期生存,从而引起病区内持续感染,需要积极采取感染控制措施;与2005年相比,近两年SICU中的主要流行株由克隆株B变为克隆株C,推测同一个病区的流行基因型可能存在流行变迁。
OBJECTIVE To investigate the homogeneity and molecular epidemiology of carbapenem-resistant Acinetobacter baumannii（CRAB） isolates selected from different wards of the Zhongshan Hospital.METHODS The identification and antimicrobial susceptibility test of A.baumannii were done according to the standardized protocol.The pulse-field gel electrophoresis（PFGE） was used to type the resistance isolates gathered in our hospital,determining whether they derived from the same clone or not.RESULTS A total of 63 strains of CRAB were recovered from patients admission between 2007 and 2008 in our hospital.A total of 11 distinct genotypic patterns were identified using PFGE（A,C-M）.In the last two years,PFGE types C and E were the dominate clone including 20 and 20 clonally related strains,respectively.Clone C dominated in SICU,while clone G1 in EICU,clone E in respiratory ward and emergency observation room.During February to June in 2005,2 different PFGE genotypes were detected in 5 strains of CRAB（A and B） from SICU,of which clone B accounted for 80.0%.None of the clone B appeared in 2007 and 2008.PFGE type A was first isolated from a patient in the respiratory ward in February 2005,and other strains in this clone were isolated from the respiratory wards and other wards of the hospital during the following years（until December 2008）.CONCLUSIONS This is the first homogeneity description of CRAB infection in hospital.PFGE types C and E are the predominant clone in hospital in the last two years and clone G1 and clone E cause the spread of CRAB infection.There′s one respective clone dominated in each ward,which suggests that the increasing rate of CRAB infections is corresponded to the spread of the close clonally related strains.In contrast to carbapenem-resistant strains collected in 2005,PFGE types have changed in 2007 and 2008.Clonally related strains can survive for a long time in hospital and cause nosocomial infections at various times in different wards.
出处
《中华医院感染学杂志》
CAS
CSCD
北大核心
2011年第3期421-424,共4页
Chinese Journal of Nosocomiology
基金
上海市重点学科建设项目资助(B115)
