Cytosolic Adenylate Cyclases & Their Involvement in Adherence and Biofilm Formation in Pathogenic Aeromonas Hydrophila

摘要: Aeromonads are inhabitants of aquatic environments and are able to infect humans and fish among other animals. In aquaculture, they are responsible for the economically important diseases of furunculosis and motile Aeromonas septicemia. Aeromonas hydrophila uses cAMP receptor protein for regulation of sugar metabolism and biofilm formation. The genome sequence of A. hydrophila shows presence of three putative adenylate cyclase (cya) genes cyaA (AHA_0470), cyaB (AHA_2412) and cyaC (AHA_3770) predicted to encode classI, classIV and classIV adenylate cyclase respectively. Insertional inactivation mutants of cya genes showed reduced biofilm formation and infectivity to Hep2 cells compared to wild type and complemented strains. Additionally promoter fusion assays suggested CYA is involved in upregulating the expression of tap and msh pilus biosynthesis genes known to be involved in attachment and biofilm formation. Our study is first to identify cyaC as a functional adenylate cyclase in Aeromonas spp. Further more to the best of our knowledge this is the first report to identify the role of all three adenylate cyclases to be involved in regulating pilin biosynthesis, adherence and cell toxicity of pathogenic Aeromonas hydrophila.