Evaluation of gene expression changes in two-componentregulatory systems of Pseudomonas aeruginosa

Background and Aim : Pseudomonas aeruginosa is an opportunistic pathogen that causes seriousnosocomial-infections. The biofilm plays a critical role in the virulence of P. aeruginosa. Biofilmformation is under-regulation of two-component regulatory systems of bacteria gacA and retS. Thebiofilm matures during a process in ۵-days, which is the outcome of equivalence in the expressionof upstream regulatory genes. This study aims to evaluate the expression of two major generegulatorsgacA and retS, during biofilm maturation in Pseudomonas aeruginosa.Methods : The biofilm producer P. aeruginosa ATCC ۱۰۱۴۵ was placed in the in-vitro conditionsof biofilm production using a micro-titer plate assay. After days ۱, ۲, and ۵, total RNA wasextracted, and the expression of gacA/retS genes measured using the relative Real-Time PCRmethod.Results : Both gacA and retS expression showed a time-dependent increase after two days.However, from ۲nd to ۵th day, a reducing expression was observed in gacA, while retS showed acontinued increasing expression in this time period.Conclusion : The results confirmed that gac and ret regulators have a direct positive effect on theexpression of genes are involved in biofilm formation of P. aeruginosa.

کلیدواژه ها:

Pseudomonas aeruginosa ، biofilm formation ، quorum sensing ، two-componentregulatory system ، gacA ، retS.