鲍氏不动杆菌生物被膜耐药机制的相关研究  

Research of biofilm resistance mechanism in Acinetobacter baumannii

作　　者：杨芬[1] 刘原[1] 柯蕊[1] 赵玉杰[1] 杨妮[1] 和平[1] 敬荣 

机构地区：[1]西安交通大学第二附属医院呼吸内科,陕西西安710004

出　　处：《中华医院感染学杂志》2017年第1期28-31,38,共5页Chinese Journal of Nosocomiology

基　　金：国家自然科学基金(81270061);陕西省科技计划项目(2010k16-01[2])

摘　　要：目的探索鲍氏不动杆菌(AB)生物被膜的耐药机制与外排泵、碳青霉烯酶基因表达的相关性,为揭示AB生物被膜耐药机制及生物被膜感染的防治提供分子学依据。方法收集临床各科室送检标本中经分离鉴定的非重复AB共152株,96孔板建立生物被膜模型,结晶紫染色法半定量检测多药耐药菌株的生物被膜形成能力;选取外排泵adeB、碳青霉烯酶OXA23基因表达阳性且生物被膜形成阳性菌株,利用改良平板法建立生物被膜模型,Real-time PCR测定各菌株浮游态及生物被膜形成不同阶段adeB及OXA23基因的表达。结果 152株AB中可形成生物被膜共136株,阳性率89.5%;生物被膜形成阳性菌株中adeB基因、OXA23基因检出阳性菌株分别为130株(96%)、78株(57%),同时检出阳性菌株共76株;所有受试临床菌株adeB基因在生物被膜形成不同阶段表达均高于浮游态,OXA23基因在生物膜形成早期表达高于浮游态,成熟后期表达低于浮游态。结论生物被膜形成可能为AB耐药的重要原因;AB生物被膜耐药可能与外排泵高表达相关;碳青霉烯酶基因高表达可能与AB生物被膜形成早期耐药相关。OBJECTIVE To study the correlation between biofilm resistance mechanisms and efflux pump,carbapen- emase gene expression in Acinetobacter baumannii so as to reveal the biofilm resistance mechanisms in A. bauman- nii and provide molecular basis for prevention of biofilm infection. METHODS A total of 152 strains of non-repeti- tive A. baumannii were isolated from submitted specimens of clinical departments, the 96 hole polyethylene plate was used to establish A. baumannii biofilms model,and the crystal-violet staining method was applied to determine the ability of biofilm formation. The strains that were positive for expression of efflux pump adeB,carbapenemase gene OXA23 and biofilm formation were selected, the biofilm model was established by using the method of modi- fied tablet, the real-time PCR was employed to determine the floating state and the expression of adeB and OXA23 in different phases of biofilm formation. RESULTS Of the 152 strains of A. baurnannii, 136 were detected positive for biofilm formation, with the positive rate 89.5%. Among the strains positive for biofilm formation, 130 （96%） were detected positive for adeB gene, and 78 （57 % ） were detected positive for OXA23 gene, and 76 were detected positive for both adeB gene and OXA23 gene. The expression of adeB gene of all the tested clinical strains was higher in the different phases of biofilm formation than in the floating state, while the expression of OXA23 gene was higher in the early stage of biofilm formation than in the floating state and was lower in the late stage of ma- ture than in the floating stage. CONCLUSION The biofilm formation may be a leading cause of the drug resistance in the A. baumannii strains~ the biofilm resistance in the A. baumannii strains may be related to the high expres- sion of efflux pump, and the high expression of carbapenemase gene may be related to the drug resistance in early stage of biofilm formation.

关 键 词：鲍氏不动杆菌 生物被膜 adeB基因 OXA23基因 

分 类 号：R378[医药卫生—病原生物学]