2017-2018年江西地区CRAB生物膜形成能力和流行特征分析

Analysis of biofilm forming capacity and epidemic characteristics of CRAB in Jiangxi region from 2017 to 2018

目的分析2017-2018年江西地区耐碳青霉烯类鲍氏不动杆菌(Carbapenem-resistant Acinetobacter baumannii,CRAB)的生物膜形成能力特征和遗传亲缘关系,为CRAB菌株的感染、播散和诊治提供参考依据。方法收集江西省11家三甲综合医院的CRAB临床分离菌株和临床资料,通过结晶紫染色法研究CRAB的生物膜形成能力,菌株的克隆进化关系则采用脉冲场凝胶电泳(PFGE)和多位点序列分型(MLST)进行分析,并观察CRAB的生物膜形成能力和克隆型别在各地域的分布是否具有差异性。结果本研究共收集184株CRAB菌株,结晶紫染色结果显示87株具有生物膜形成能力,各地区间菌株生物膜形成能力无统计学差异。PFGE结果显示,184株CRAB可分为25个不同的聚类型别,其中占比最大的是聚类型别A(33.7%,62/184)和聚类型别B(28.8%,53/184)。MLST结果显示,所有菌株可分为14个不同序列型别(ST型别),优势序列型别为ST 829,其次是ST new1、ST 1417,其中ST 829(χ^2=10.461,P=0.033)和ST 1417(χ^2=10.116,P=0.039)在各地区间的分布具有统计学差异,其余11个ST型别零散分布于江西各地。结论各地区间CRAB的生物膜形成能力差异无统计学意义,但菌株具有克隆多态性,ST 829、ST new1、ST 1417为其优势序列型别,ST 829和ST 1417在地区间的分布差异具有统计学意义。

OBJECTIVE The characteristics of biofilm formation capacity and genetic relationship in strains of carbapenem-resistant Acinetobacter Baumannii(CRAB) in Jiangxi province from 2017 to 2018 were analyzed to provide references for the control of infection and dissemination, diagnosis and treatment the infection of CRAB strains. METHODS CRAB strains clinical isolated and clinical data from 11 third-grade a general hospitals in Jiangxi Province from 2017 to 2018 were collected. The biofilm formation capacity of CRAB was studied by crystal violet staining, and the clonal evolution relationship of the strains was analyzed by pulsed field gel electrophoresis(PFGE) and multi-site sequence typing(MLST), to observe whether CRAB′s biofilm formation capacity and the distribution of clone types in various regions were different. RESULTS A total of 184 CRAB strains were collected in this study. Crystal violet staining results showed that 87 strains had biofilm forming ability, and there was no statistical difference in biofilm forming ability among strains in different regions. According to the PFGE results, the 184 CRAB were divided into 25 different types, of which the largest proportion was type A(62/184, 33.7%) and type B(53/184, 28.8%). MLST results showed that all strains could be divided into 14 different sequence types(STs), of which the dominant STs were ST 829, followed by ST new1 and ST 1417. The distribution of ST 829(χ^2=10.461, P=0.033) and ST 1417(χ^2=10.116, P=0.039) in different regions were significantly different. The rest of the 11 types were scattered around Jiangxi province. CONCLUSION There was no significant difference of biofilm formation ability of CRAB among different regions, but the strains showed clonal polymorphism, with the dominant sequence types of ST 829, ST New1 and ST 1417, and the distribution of ST 829 and ST 1417 in different regions was significant.