重症监护病房鲍氏不动杆菌5年耐药监测及同源性分析

目的了解重症监护病房鲍氏不动杆菌的临床分布和耐药变迁,旨在为制定预防和控制其医院感染的措施提供依据。方法采用全自动微生物分析系统VITEK-AMS60对566株鲍氏不动杆菌进行鉴定,采用纸片扩散法(K-B法)对临床分离株作药敏试验,参照CLSI为判断标准,耐药数据分析采用WHONET5.4软件,同时以脉冲场凝胶电泳进行其同源性分析,PCR检测相关耐药性基因。结果 2004年1月～2008年12月共分离出鲍氏不动杆菌566株,主要来源于呼吸道标本,分离率为86.9%,分离株和耐药率有逐年增加的趋势;连续5年监测了18种抗菌药物,12种抗菌药物耐药率均90.0%,亚胺培南95.6%、美罗培南91.4%、头孢他啶76.7%、阿米卡星75.1%、庆大霉素70.3%、头孢哌酮/舒巴坦57.3%、多黏菌素E20.0%;脉冲场凝胶电泳研究发现34株耐亚胺培南鲍氏不动杆菌为同一耐药克隆株,在重症监护病房呈暴发流行;PCR明确产OXA-23型碳青酶烯酶,未检出OXA-24、IMP、VIM基因型。结论多药耐药和泛耐鲍氏不动杆菌逐年增多,头孢哌酮/舒巴坦和多黏菌素E是治疗多药耐药鲍氏不动杆菌的首选药物,连续动态监测重症监护病房鲍氏不动杆菌的耐药变迁,对临床治疗其引起的感染具有十分重要的意义。

Antibiotic Susceptibility and Homological Profile in Acinetobacter baumannii Isolated During Five Years

OBJECTIVE To survey the prevalence of the Acinetobacter baumannii isolated from ICU and related trend of antibiotic susceptibility during from Jan 2004 to Jun 2008,and to provide a cue for preventing and controlling hospital acquired infections.METHODS According to Clinical and Laboratory Standards Institute (CLSI) Guidelines of the USA,the susceptibility for antibiotic was determined by K-B test and the data were analyzed by WHONET 5.4,following the identification of 566 strains of A.baumannii by VITEK-AMS60.Homological profile of these isolates was performed by pulsed field gel electrophoresis(PFGE),along with PCR detecting related anti-drug genes.RESULTS A total of 566 strains of A.baumannii were isolated during the fiveyear period with the majority of 86.9% from sputum specimen.The incidences of A.baumannii isolates and antibiotic resistance increased annually.Among all of the 18 antimicrobial agents monitored in the five years,12 presented resistance rate above 90.0%,with imipenem being resistance against A.baumannii at the rate of 95.6%,meropenem 91.4%,ceftazidime 76.7%,amikacin 75.1%,gentamicin 70.3%,cefperazone/sulbactam 57.3%,and polymyxin E 20.0%,respectively.PFGE pattern of 34 isolates revealed the identical clone relationships of the resistant A.baumannii,confirming the outbreaks of resistant strains in ICU.OXA-23 type carbapenemase was detected in all isolates, but none of the OXA-24, IMP and VIM for all isolates.CONCLUSIONS The muhidrug-resistant A.baumannii is increasing annually,as well as pandrug-resistant one.Cefoperazone/sulbactam and polymyxin E are be priority drugs to treat infections caused by multidrug-resistant A.baumannii.It is vital to undertake a continuous monitoring of the trend of antibiotic susceptibility of A baumannii from ICU for effective therapyeutic options.