REGULATION OF Salmonella BIOFILM DEVELOPMENT BY DIFFERENT MECHANISM ACTIVATION OF RCSCDB SYSTEM

MARIA CECILIA LECCESE TERRAF; MARIELA A. TORRES; MARÍA DE LAS MERCEDES PESCARETTI; MÓNICA A. DELGADO

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias. LIII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2017

The RcsCDB regulatory system has an important role in the bacterialphysiology, controlling the capsule synthesis and motility behavior.Previously studies showed that the RcsCDB system participatein biofilm development. Bacterial biofilms are complex communitiesconsisting of microorganisms embedded in a self-produced extracellularmatrix. The RcsCDB phosphorelay system participates inthe response to extracytoplasmic stress signaling that affect the cellenvelope and are responsible for the system activation. In this workwe analyzed if different RcsCDB activation conditions affect thebiofilm formation in Salmonella Typhimurium. We here investigatedwhether some of the RcsCDB activation conditions have the abilityto regulate the synthesis of the pellicle in LB medium, producing reddry and rough (RDAR) morphotype on Congo red and brilliant blueagar plates, and in crystal violet binding assay. For these propose,we studied the biofilm phenotype in strains harboring the prcsB andprcsC plasmids, and in tolB and rcsC11 mutants as RcsCDB activationconditions. Moreover, we measured the transcription levels ofbapA gene in these strains in order to investigate whether the activationcondition of RcsCDB phosphorelay could somehow be affectingthe expression of this biofilm reporter gene. Taken together, ourresults demonstrated that the RcsCDB system activation modulatesthe bapA gene in a direct pathway, and consequently the Salmonellabiofilm development.