血流感染患者分离的鲍曼不动杆菌同源性分析及毒力基因检测

摘要

目的 对临床血流感染患者分离的鲍曼不动杆菌耐药性、同源性和毒力基因进行分析.方法 连续收集2013年7月至2014年7月全国17家医院患者血标本分离的鲍曼不动杆菌90株,采用Vitek-2全自动微生物分析系统对菌株进行鉴定及药敏试验,采用脉冲场凝胶电泳试验对其进行分型,同时采用PCR方法检测碳青霉烯酶和毒力基因.结果 90株鲍曼不动杆菌中75株为多重耐药菌株,脉冲场凝胶电泳将多重耐药鲍曼不动杆菌分为8个克隆型,其中A型(51株)、B型(14株)为主要克隆型,不同医院流行的克隆型不同,大部分医院以A克隆型为主,A克隆型仅对头孢哌酮/舒巴坦、阿米卡星、替加环素保持较高的敏感率;毒力基因abaI、cusE、ompA、bap、bfms的检出率均较高,分别为93.3%(84/90)、92.2%(83/90)、100.0%(90/90)、84.4%(76/90)、92.2%(83/90).7株黏液表型菌株,全部是多重耐药鲍曼不动杆菌,均属于B克隆型且毒力基因全部阳性.结论 血流感染患者分离的多重耐药鲍曼不动杆菌主要以A克隆型为主.abaI、bap和bfms生物膜相关基因可能与多种药物耐药性相关.黏液表型菌株可能具有更强的毒力并且易于播散,应引起临床重视.%Objective The epidemiology of Acinetobacter baumannii isolates from bloodstream infections,their antibiotic resistance profiles and virulence-associated factors were studied.Methods A total of 90 isolates from 17 hospitals were collected from the patients with bloodstream infections during July 2013 and July 2014.Vitek-2 Compact system was used for identification of the strains and antibiotic susceptibility testing.The epidemiology was studied by pulsed-field gelectrophoresis(PFGE).Drug-resistant genes and associated virulence genes were amplified by PCR.Results According to antimicrobial susceptibility testing,75 isolates are multi-drug resistant Acinetobacter baumannii.PFGE results showed that 75 multi-drug resistant Acinetobacter baumannii isolates belonged to eight clone types(A to H),with the A (n=51)and B (n=14)clone being the dominant PFGE clone types.Different clone isolates spread in different hospitals.Most of the hospitals were given priority to with clone A.Clone A only maintaining high sensitive rate to cefoperazone/sulbactam、amikacin and tigecycline.Virulence gene abaI,cusE,ompA,bap,bfms detection rates are 93.3% (84/90),92.2% (83/90),100.0% (90/90),84.4% (76/90),92.2% (83/90),respectively.There were 7 mucoid isolates,which are all multi-drug resistant Acinetobacter baumannii,all belong to clone B and all associated virulence genes can be detected.Conclusions The dominant clone type of multi-drug resistant Acinetobacter baumannii from bloodstream infections is clone A.The abaI-,bap-and bfms-positive strains are associated with a higher incidence of antibiotic resistance in most types of antimicrobials.The acquisition of mucous type may indicate the emergence of virulent strains,which should be paid attention to during clinical treatment.