An Investigation of the Role of Vibrio Vulnificus rbdA and Vibrio Parahaemolyticus sypA in Biofilm Formation

Vibrio vulnificus and Vibrio parahaemolyticus are both bacteria that cause human infection. V. vulnificus has a polysaccharide locus, rbd, responsible for bacterial aggregation, a form of biofilm. This locus is conserved in V. parahaemolyticus and in the non-pathogen V. fischeri. In V. fischeri, the polysaccharide locus, syp, has been extensively characterized and shown to be important for biofilm formation. In V. fischeri, the first gene, sypA, is critical for biofilm formation. V. fischeri biofilm-proficient strains form wrinkled colonies. In contrast, sypA mutants form smooth colonies, indicating a lack of biofilm formation. To understand the function of RbdA and SypAVP, proteins encoded by the first genes in the respective polysaccharide loci, in biofilm formation, we hypothesized we could use the well-characterized V. fischeri model of biofilm formation. I found that rbdA and sypAVP are able to promote biofilm formation in V. fischeri. Additionally, RbdA and SypAVP function appear to be controlled by SypE, the negative regulator of SypA in V. fischeri