Structural features of biofilm formation by Bordetella pertussis. Role of BvgAS system

SERRA, D; PEREZ VIDACOVIKS, M. L.; RODRIGUEZ, ME; BOSCH, A.; YATORNO, O

Paris, Francia

Congreso; 8th International Symposium Saga of the genus Bordetella; 2006

Instituto Pasteur de Paris

Bordetella pertussis is a persistenthuman pathogen able to form biofilms under certain in vitro conditions. In this study, we examined the contribution  of B. pertussis virulent phenotype and selected Bvg-regulated virulence factors (filamentous hemaglutinin, Fimbriae, and Adenylate Cyclase toxin) to different dofferent stages of biofilm formation. Wild type and mutant B. pertussis strains defective in the above mentioned virulence factors were cultured in continuous flow chamber systems inon Zn Se windows or Borosilicate coverslips. Bacterial growth and biofilm formation was monitored over the time by FT-IR spectroscopy, fluorescence microscopy, and scanning laser confocal microscopy (SLCM). Microscopy imageswere analysed by LSM 5 Browser software and COMCSTAT software in oreder to obtain quantitative information of biofilm structures. Our resultas indicate that the virulent phase is highly relevant for B. pertussis biofilm development on abiotic surfaces. Among the Bvg-regulated factors, FHA demonstrated to be critical not only for early attachment but also for later progress towards the development of mature biofilm. Neither Adenylate cyclase  nor Fimbriae were found involved in the initial attachment events of B. pertussis to abiotic substrates.- However, Adenylate Cyclase toxin showed to play a role at later stages of biofilm growth.