儿科患者分离鲍曼不动杆菌耐药性及分子流行病学研究

Drug resistance and molecular epidemiology of Acinetobacter baumannii isolated from pediatric patients

目的分析儿科患者分离出的鲍曼不动杆菌的耐药性及分子流行病学特征。方法以2016年1月至2018年6月内蒙古医科大学附属医院住院患者分离的医院感染鲍曼不动杆菌作为研究对象,采用Vitek-2 Compact全自动微生物鉴定及药敏分析系统进行鉴定及药敏试验,采用脉冲场凝胶电泳(PFGE)方法及多位点序列分型(MLST)进行菌株同源性分析。结果共收集鲍曼不动杆菌临床分离株94株,其中42株来自儿科患者,52株来自成人患者。儿科分离株对亚胺培南、美罗培南和替加环素耐药率分别为7.1%、7.1%和0,成人分离株对这3种抗生素耐药率分别为67.3%、54.8%和5.5%。PFGE分型结果显示,94株菌共分为49个基因型(X1~X49型),52株成人分离株分布于22个基因型,42株儿童分离株分布于33个基因型中。优势基因型为X23型(21株,22.3%),其中成人分离株为18株(85.7%),儿童分离株为3株(14.3%)。X23基因型菌株对碳青霉烯类耐药率为100%,明显高于其他基因型菌株。MLST分型结果显示,X23基因型为ST195,归属于克隆复合体92(CC92)克隆群。结论内蒙古医科大学附属医院鲍曼不动杆菌儿童分离株总体耐药率明显低于成人分离株,基因型多样化特征明显,优势基因型归属CC92克隆群,为我国多地分离优势克隆株。

Objective To analyze the drug resistance and molecular epidemiological characteristics of Acinetobacter baumannii isolated from pediatric patients.Methods Acinetobacter baumannii isolated from patients hospitalized in Inner Mongolia Medical University Affiliated Hospital from January 2016 to June 2018 was collected.Vitek-2 Compact automatic microbiological identification and drug sensitivity analysis system was used to identify and test the drug sensitivity of Acinetobacter baumannii isolates,and pulse field gel electrophoresis(PFGE)and multilocus sequence analysis(MLST)were applied to the homology analysis of the strains.Results A total of 94 clinical isolates of Acinetobacter baumannii were collected,of which 42 strains were isolated from pediatric patients and 52 strains from adult patients.The drug resistance rates of pediatric isolates to Imipenem,and Meropenem and Tigecycline were 7.1%,7.1%and 0,respectively,and the drug resistance rates of adult isolates to these 3 antibiotics were 67.3%,54.8%,and 5.5%,respectively.The results of PFGE typing showed that 94 strains were divided into 49 genotypes(X1-X49 type),52 adult strains were distributed in 22 genotypes,and 42 pediatric strains were distributed in 33 genotypes.The dominant genotype was X23(21 strains,22.3%),of which 18 strains(85.7%)were adult isolates and 3 strains(14.3%)were children isolates.The drug resistance rate of X23 genotypes to carbapenems was 100%,which was significantly higher than that of other genotypes.The results of MLST genotyping showed that X23 genotype was ST195,which belonged to clonal complex(CC92)clone.Conclusions The overall drug resistance rate of Acinetobacter baumannii isolates in Inner Mongolia Medical University Affiliated Hospital was significantly lower than that of adult isolates,and the diversity of genotypes was obvious.The dominant genotypes of the strains belongs to the CC92 clone population,and is the dominant clone strain in many places of our country.