Regulation of Salmonella biofilm development by different mechanism activation of RcsCDB system.

LECCESE TERRAF M.; TORRES M. A.; PESCARETTI M.; DELGADO M. A.

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

The RcsCDB regulatory system has an important role in the bacterial physiology, controlling the capsule synthesis and motility behavior. Previously studies showed that the RcsCDB system participate in biofilm development. Bacterial biofilms are complex communities consisting of microorganisms embedded in a self-produced extracellular matrix. The RcsCDB phosphorelay system participates in the response to extracytoplasmic stress signaling that affect the cell envelope and are responsible for the system activation. In this work we analyzed if different RcsCDB activation conditions affect the biofilm formation in Salmonella Typhimurium. We here investigated whether some of the RcsCDB activation conditions have the ability to regulate the synthesis of the pellicle in LB medium, producing red dry and rough (RDAR) morphotype on Congo red and brilliant blue agar plates, and in crystal violet binding assay. For these propose, we studied the biofilm phenotype in strains harboring the prcsB and prcsC plasmids, and in tolB and rcsC11 mutants as RcsCDB activation conditions. Moreover, we measured the transcription levels of bapA gene in these strains in order to investigate whether the activation condition of RcsCDB phosphorelay could somehow be affecting the expression of this biofilm reporter gene. Taken together, our results demonstrated that the RcsCDB system activation modulates the bapA gene in a direct pathway, and consequently the Salmonella biofilm development.