亚胺培南耐药鲍曼不动杆菌外膜蛋白与外排泵基因adeB分析

Analysis on the outer membrane protein and efflux pump gene adeB among the imipenem-resistant Acinetobacter baumannii

目的了解耐亚胺培南鲍曼不动杆菌中外膜蛋白表达以及外排泵基因adeB的分布情况。方法收集该院2008年9月至2010年12月亚胺培南耐药鲍曼不动杆菌65株,采用PCR方法扩增外膜蛋白CarO编码基因及外排泵adeB基因;聚丙烯酰胺凝胶电泳(SDS-PAGE)分析耐药菌与敏感菌外膜蛋白表达的差异。结果 65株菌均检出CarO编码基因与adeB基因,其中2株菌CarO编码基因上游存在ISAba1插入序列。SDS-PAGE显示,耐药菌株与敏感菌株在外膜蛋白上存在主要有大约24×103蛋白的缺失和48×103蛋白的高表达。结论外膜蛋白CarO和adeB基因在亚胺培南耐药鲍曼不动杆菌中广泛存在,adeB基因的高表达以及外膜蛋白表达的差异是鲍曼不动杆菌对亚胺培南耐药的重要机制。

Objective To investigate the distribution of outmembrane protein encoding and efflux pump gene adeB among the imipenem-resistant Acinetobacter baumannii. Methods 65 imipenem-resistant Acinetobacter baumannii were collected from 2008 September to 2010 December. Polymerase chain reaction（PCR） was implemented to screen the carO and adeB genes. SDS-PAGE was carried out to analyze the differences on the expressions of the Outer membrane proteins between the imipenem-resistant and susceptible strains. Results All the 65 strains contained the carO and adeB genes. Additionally, ISAbal was detected in the up- stream of CarO coding genes in two strains. SDS-PAGE displayed that there was approximately a 24-kDa protein missing and a higher expression in 48-kDa protein. Conclusion There is a wide distribution of CarO encoding and adeB genes among imipenem re- sistance Acinetobacter baumannii. And imipenem resistance may result from the high expression of adeB and different expression of outmembrane proteins,