LAP PROTEINS ARE A C-DI-GMP EFFECTOR SYSTEM THAT CONTROLS BIOFILM IN Bordetella bronchiseptica

AMBROSIS N; SISTI F; FERNANDEZ J

Rosario

Congreso; L Reunión SAIB 2014; 2014

Sociedad de Investigacines Bioquímicas y Biología Molecular

Bordetella bronchiseptica is a respiratory pathogenic bacterium that forms biofilm-like structures. Previously, we determined that c-di-GMP levels modified ability to form biofilm. However, the bacterial factors involved in biofilm formation has not been yet determined. In Pseudomonas fluorescens a c-di-GMP effectors system controls biofilm formation. LapA is a surface adhesin and its binding to the cell surface is controlled by LapD, in response to c-di-GMP. LapD promotes biofilm formation through LapA accumulation. LapG cleaves LapA, freeing the adhesin and preventing biofilm. Accordingly, when LapG is overexpressed or LapD is absent biofilm is prevented. Homologous to Lap proteins were identified in B. bronchiseptica. When LapGBb was overexpressed less biofilm was formed on abiotic surfaces. Moreover, biofilm structures observed by fluorescent microscopy over glass surface and epithelial cells were significantly different. Protruding structures typically observed in wild type biofilms were rarely observed in Bb-LapGBb. To evaluate if LapDBb is involved in biofilm formation, lapDBb gene was deleted. Surprisingly, LapDBb deletion enhanced biofilm formation in B. Bronchiseptica.