耐碳青霉烯鲍曼不动杆菌临床分离株的流行病学与耐药机制研究  

Epidemiology and resistance mechanism study of carbapenem-resistant Acinetobacter baumannii

作　　者：张广慧[1] 曹雪萍[2] 俞静[2] 刘瑛[2] 葛艳[1] 

机构地区：[1]同济大学医学院,上海200092 [2]上海交通大学医学院附属新华医院检验科,上海200092

出　　处：《检验医学》2015年第1期53-57,共5页Laboratory Medicine

摘　　要：目的了解耐碳青霉烯类抗菌药物的鲍曼不动杆菌流行病学情况以及耐药机制,帮助临床合理使用抗菌药物,为控制医院感染提供依据。方法收集耐碳青霉烯类抗菌药物的鲍曼不动杆菌110株及敏感株6株,进行来源病区和标本种类的统计分析;应用重复序列聚合酶链反应(REP-PCR)进行基因型分型;使用PCR检测β-内酰胺酶基因(OXA、IMP、VIM等)及外排泵编码基因(ade A、ade B、ade C、ade J、ade G)的携带情况;采用实时荧光定量PCR对比耐药菌株与敏感菌株的外排泵基因表达量的差异。结果 110株菌株主要来自痰标本,重症监护病房(ICU)分离率最高;所有菌株REP-PCR电泳图谱分为A^G 7型,110株耐药菌株均为A型,且均被检测到含有OXA-23、OXA-51基因,均未检测到含有OXA-24、OXA-58、IMP-1、IMP-2、VIM-1、VIM-2基因;外排泵编码基因ade A、ade B、ade C、ade J及ade G的阳性率均为100%;耐药菌株外排泵编码基因ade A、ade B、ade C表达量明显高于敏感菌株。结论耐碳青霉烯类鲍曼不动杆菌的流行型别基本相同,均为A型,应引起临床医护人员的高度重视;β-内酰胺酶基因(OXA-23、OXA-51)的表达以及外排泵基因(ade A、ade B、ade C)的过度表达与其对碳青霉烯类抗菌药物的耐药性有关。Objective To understand the drug resistance mechanisms and epidemiology of carbapenem-resistant Acinetobacter baumannii in order to guide the rational use of antibiotics and to provide the reference for the control of nosocomial infections. Methods A total of 116 Acinetobacter baumannii(110 carbapenem-resistant isolates and 6carbapenem-sensitive isolates) isolated from clinical specimens were classified and analyzed according to endemic areas and specimen types. The isolates were analyzed by repetitive-sequence polymerase chain reaction(REP-PCR) for genotyping. Beta-lactamase genes(OXA,IMP,VIM and soon) and efflux pump-encoding genes(ade A,ade B,ade C,ade J,ade G) were amplified by PCR. Real-time fluorescence quantitation PCR was performed to compare the expression level of the efflux pump-encoding genes in resistant and sensitive isolates. Results The isolation rate of resistant isolates in intensive care unit(ICU) was the highest-level,and the isolates were mainly isolated from sputum. The genotype types of carbapenem-resistant and-sensitive Acinetobacter baumannii were classified into 7 categories by REPPCR. All the carbapenem-resistant isolates were type A. OXA-23 and OXA-51 were positive in 110 carbapenem-resistant isolates. However,OXA-24,OXA-58,IMP-1,IMP-2,VIM-1 and VIM-2 could not be detected in all the isolates. The positive rates of the efflux pump-encoding genes(ade A,ade B,ade C,ade J and ade G) were 100%. The expression level of efflux pump-encoding genes(ade A,ade B,ade C) in resistant isolates was significantly higher than that in sensitive isolates. Conclusions The main popular type of carbapenem-resistant Acinetobacter baumannii is type A.Clinical staff should pay attention to this phenomenon. The expression of OXA-23 and OXA-51 overexpression of ade A,ade B and ade C efflux pump-encoding gene may play an important role in carbapenem-resistant Acinetobacter baumannii.

关 键 词：鲍曼不动杆菌 Β-内酰胺酶 外排泵 重复序列聚合酶链反应 实时荧光定量聚合酶链反应 

分 类 号：R446.5[医药卫生—诊断学]