重症监护病房环境与临床分离耐碳青霉烯类鲍曼不动杆菌的REP-PCR分型研究

Genotyping of carbapenem-resistant Acinetobacter baumannii acquired from environment and patients in intensive care units by REP-PCR

目的调查上海市重症监护病房（ICU）环境中耐碳青霉烯类鲍曼不动杆菌（CRAB）的流行型别，并分析ICU的环境分离株与临床分离株的同源性。方法对上海市21所医院ICU环境分离到的61株CRAB及其中一所医院（S医院）ICU临床分离到的14株CRAB，采用DiversiLab自动化重复序列（REP）．PCR分型系统，进行基因分型。结果6l株ICU环境分离的CRAB共分7型，其中Gl型又分3个亚型，共46株细菌，占全部细菌的75．4％，分布于上海市的13所医院；G2、G3、G4、G5、G6和G7型分别为8株（13．1％）、2株（3．3％）、1株（1．6％）、1株（1．6％）、2株（3．3％）和1株（1．6％）。在检出CRAB的13所医院中，除了D医院外，其他医院均分离到G1型CRAB。上海市S医院ICU共检出25株CRAB（14株临床株和11株环境株），分4型：其中G1型17株，为主要流行型别。由临床株和环境株的分布示意图显示：在外科ICU（SICU）中，环境株和临床株均以Gl型为主，多个邻近床位病人检出G1型CRAB；心外科ICU（CICU）环境株以G1型为主，临床株以G2型为多，其中19床的病人及周围环境均检出G1型CRAB。结论上海市ICU环境中普遍存在Gl型CRAB流行株，各医院ICU环境中存在流行株交叉污染的现象，ICU临床分离的CRAB与环境分离株有较高的相关性。应加强ICU环境消毒和手卫生，防止医院感染的暴发和流行。

Objective To investigate the genotype of carbapenem-resistant Acinetobacter bauman- nii （CRAB） acquired from intensive care units （ICUs） environment in Shanghai hospitals and to evaluate the gene homology of CRAB isolated from patients and environment in ICUs in Shanghai hospital. Methods Sixty-one CRAB isolated from ICUs environment in Shanghai hospitals and 14 strains isolated from ICUs patients in S hospital were typed by REP-PCR based DiversiLab system. Results There were 7 types of the CRAB isolated from ICUs environment in Shanghai hospitals. Type G1 was the dominant type, accounting for 75.4% of all CRAB, mainly in 13 hospitals in Shanghai. The percentage of the 7 types CRAB strains were 75.4%, 13.1%, 3.3%, 1.6%, 1.6% ,3.3% and 1.6%, respectively. Except for 1 strain of type G6 isolated in D hospital, type G1 CRAB was identified in every hospital which was isolated CRAB. There were 25 strains isolated from patients and environment in S hospital ICUs, which were divided into 4 types. Type G1 was the dominant type mainly distributed in SICU and CICU, including 9 from patients and 8 from envi- ronment. The distribution diagram of environmental and patients＇ strains indicated that the patients in adja- cent bed isolated G1 CRAB in SICU and a patient in CICU and its surrounding environment both isolated G1 CRAB. Conclusion Type G1 is the dominant type in ICUs environment in Shanghai hospitals. There are inter-hospital transmission of CRAB in ICUs environment and highly homology of CRAB isolated from patients and environment in ICUs in Shanghai hospitals. Active surveillance of infection and colonization by CRAB, together with implementation of enhanced control strategies should be taken to eradicate CRAB in ICU environment.