多重耐药铜绿假单胞菌群体感应系统与主动外排基因表达的研究  

Gene expression of quorum sensing system and active efflux gene in clinical multidrug resistant Pseudomonas aeruginosa

作　　者：李美芬[1] 徐卫东[1] 王莹超[1] 解范迪[2] 

机构地区：[1]南京医科大学附属苏州医院检验科,江苏苏州215008 [2]上海市江湾医院检验科,上海200434

出　　处：《中国微生态学杂志》2011年第12期1115-1118,共4页Chinese Journal of Microecology

摘　　要：目的研究临床多重耐药铜绿假单胞菌群体感应(QS)系统与主动外排泵MexAB-OprM系统基因表达水平与抗生素耐药关系。方法收集苏州市立医院和上海市江湾医院2011年2月至6月间临床标本中分离的铜绿假单胞菌,定量分析细菌生物被膜形成能力;MIC法检测细菌抗生素耐药性,用多重聚合酶链反应(PCR)扩增群体感应系统lasI、lasR及主动外排泵系统mexA基因,实时定量逆转录RT-PCR检测lasI、lasR和mexA基因的相对表达量。结果临床样本分离出84株铜绿假单胞菌,其中产生物被膜菌58株,占比69%;多重耐药菌共24株,占比28.6%;多重耐药菌株中产生物被膜有11株,占45.8%;多重耐药菌中mexA基因表达上调有18株,占75%;lasI基因表达上调有8株,占33.3%。结论多重耐药菌株的生物被膜形成率显著低于非多重耐药组,多重耐药铜绿假单胞菌的主动外排泵MexAB-OprM系统基因表达出现显著上调,生物被膜菌的lasI基因表达显著上调而lasR基因的表达无明显变化。Objective To investigate the gene expression of quorum sensing （QS） systems and active efflux pump MexAB-OprM in clinical muhidrug resistant Pseudomonas aeruginosa and analyze the association with antibiotic resistance. Method Clinical isolates of Pseudomonas aeruginosa were collected in Suzhou municipal hospital and Shanghai Jiangwan hospital from February to June, 2011. The bacterial biofilm forming ability was detected by quantitative assay; bacterial antibiotic resistance was detected by minimum inhibitory concentration （MIC） method ; lasI, /asR genes of quorum sensing system and mexA gene of active efflux pump system were analysed by using a multiplex polymerase chain reaction （PCR） ; Quantitative real-time polymerase chain reaction was performed to measure mRNA expression of genes lasI, lasR and mexA. Result There were 58 biofilm-producing Pseudomonas aeruginosa strains and 24 multidrug-resistant Pseudomonas aeruginosa strains in the 84 clinical isolates, accounting for 69% and 28.6%, respectively. Among the 24 multidrug-resistant strains, 11 （45.8%） were biofilm-producing bacteria. 18 strains （75%） had up-regulated expression of mexA and 8 strains （ 33.3% ） had upregulated expression of lasI. Conclusion The biofilm formation of multiple drug-resistant Pseudomonas aeruginosa strains are significantly lower than that of non-multiple drug-resistant strains. The expression of active efflux pump MexAB-OprM gene is significantly up-regulated in multiple drug-resistant Pseudomonas aeruginosa. The expression of lasI gene in biofilm-producing bacteria is significantly increased while no obvious change in that of lasR gene.

关 键 词：多重耐药铜绿假单胞菌 主动外排基因 抗生素耐药 生物被膜菌 

分 类 号：R378.991[医药卫生—病原生物学]