新生儿下呼吸道多重耐药鲍氏不动杆菌感染与环境同源性追踪分析

Follow-up study of environmental homology of neonates with lower respiratory tract infection due to multidrug-resistant Acinetobacter baumannii

目的查找新生儿下呼吸道多重耐药鲍氏不动杆菌感染与环境菌株的同源性,追踪可能的传播链,为下一步干预措施的制定提供科学依据。方法对医院2017年6月-2017年12月培养出多重耐药鲍氏不动杆菌的下呼吸道感染患儿进行环境追踪,通过16SrRNA基因测序和系统进化树进行菌株鉴定,对分离到的鲍氏不动杆菌采用Eric-PCR和MLST进行基因同源性分析。结果共采集多重耐药鲍氏不动杆菌感染患儿环境标本207份,其中阳性标本61份,占29.47%;16SrRNA基因同源性及系统进化分析显示,15株细菌属于鲍氏不动杆菌菌种;Eric-PCR得到A-I型9个型别,综合MLST分析结果显示,2号患儿痰液标本、输液泵、责任护士护士服,1号温箱表面与同期采样病房的电脑键盘,及3号患儿监护仪和责任护士手为同一ST2型别。其余型别为ST195,ST208,ST191,ST75,ST92,ST235。结论通过对新生儿下呼吸道多重耐药鲍氏不动杆菌感染患儿环境追踪发现,与环境分离菌株具有同源性,说明有效控制环境污染有助于防控感染传播扩散。

OBJECTIVE To find out the homology between the multidrug-resistant Acinetobacter baumannii strains isolated from neonates with lower respiratory tract infection and the environmental strains and track the potential transmission chain so as to provide scientific basis for development of intervention measures.METHODS The environmental follow-up was conducted for the neonates with lower respiratory tract infection from who the multidrugresistant A.baumannii strains were isolated from Jun 2017 to Dec 2017,the strains were identified by using 16 S rRNA gene sequencing and phylogenetic tree,and the genetic homology of the isolated A.baumannii strains was analyzed by means of Eric-PCR and MLST.RESULTS A total of 207 environmental samples were collected from the neonates with A.baumannii infection,61（29.47%）of which were positive.The results of the detection of 16 S rRNA gene homology and phylogenetic tree analysis showed that 15 strains were A.baumannii.Eric-PCR indicated that 9 genotypes were obtained,ranging between A and I.The result of comprehensive MLST analysis showed that the strains isolated from the sputum specimens of No.2 neonates,injection pump,uniforms of responsible nurses and surfaces of No.1 incubator belonged to the ST2,which were the same as the strains isolated from the computer keyboards in wards,monitor of No.3 children and hands of responsible nurses;the other genotypes were ST195,ST208,ST191,ST75,ST92 and ST235.CONCLUSIONThe environmental follow-up shows that the A.baumannii strains isolated from the neonates with lower respiratory tract infection have the homology with the environmental strains,indicating that effective control of environmental pollution may facilitate the control of transmission of the infections.