铜绿假单胞菌在急性下呼吸道感染患者中生物被膜形成与群体感应系统基因相关性分析

Analysis the correlation between biofilm formation of Pseudomonas aeruginosa and quorum-sensing system gene in patients with acute lower respiratory tract infection

目的:探讨在急性下呼吸道感染患者体内铜绿假单胞菌群体感应系统中Las系统和Rhl系统的表达及与其生物被膜形成的相关性。方法:以铜绿假单胞菌临床分离株为研究对象,检测群体感应系统中Las系统和Rhl系统相对表达量及生物被膜形成能力,分析Las系统和Rhl系统表达量与生物被膜形成能力的相互关系。结果:测定的120株铜绿假单胞菌临床菌株中,Las信号系统的LasI和LasR基因相对表达与生物被膜形成均呈正相关(P<0.001),其中第1天分离的临床株中LasI和LasR基因相对表达量与生物被膜生成量呈正相关(P<0.01),第14天分离的临床株中LasI基因相对表达量与生物被膜生成量有密切正相关性(P<0.001),LasR基因相对表达量与生物被膜生成量呈正相关(P<0.05)。Rhl信号系统的RhlI和RhlR基因相对表达量与生物被膜生成量密切正相关(P<0.001),其中第1天分离的菌株中RhlI和RhlR基因相对表达量与生物被膜生成量密切正相关(P<0.001),而第14天分离的菌株中RhlI和RhlR基因相对表达量与生物被膜生成量无相关性。结论:铜绿假单胞菌的群体感应系统中Las信号系统和Rhl信号系统与生物被膜形成密切相关,在生物被膜的形成过程起到关键作用。

Objective To investigate the correlation between expression of Las and Rhl signal system in quorumsensing （QS） system and biofilm formation in Pseudomonas aeruginosa acute lower respiratory tract infection. Methods To detect the relative gene expression of Las and Rhl signal system and biofilm forming ability, analyzing the correlation between expression of Las and Rhl system and biofilm forming ability. Results Of the 120 clinically isolated Pseudomonas aeruginosa strains, expression of Las signal system Lasl and LasR relative gene was positively correlated with biofilm formation （ P〈0.001 ）; the first day clinical isolated strains had their LasI and LasR relative gene expression positively correlated with biofilm formation （P〈0.01）, day 14 clinical isolated strains had their LasI relative gene expression closely positive correlated with biofilm formation （P〈0.001） and LasR relative gene expression positively correlated with biofilm formation （P〈0.05）. Rhl signal system RhlI and RhlR relative gene expression was closely positive correlated with biofilm formation （P〈0.001）; the first day Rhll and RhIR relative gene expression and biofilm formation was closely positive correlated （P〈0.001）, and the 14 days RhlI and RhlR relative gene expression was not correlated with biofilm formation. Conclusions Las and Rhl signal system in QS system had a close correlation with biofilm formation and played a key role in the process of biofilm formation in Pseudomonas aeruginosa.