Impact of Lactococcus lactis spp. lactis Bio Adhesion on Pathogenic Bacillus cereus Biofilm on Silicone Flowing System

Bacillus cereus is a food pathogen that can attach on most of the surfaces and form biofilms, which facilitate the persistence and resistance toward antimicrobials. The aims of this study were (i) to characterize the structural dynamics of B. cereus sessile growth in two nutritional environments (with or without a nutrient flow), and (ii) to evaluate the impact of bio adhesion of Lactococcus lactis on B. cereus biofilm. Significantly greater biofilm volume and thickness were observed under dynamic conditions than under static conditions after 48 h and B. cereus biofilm was highly organized. The variation of physico-chemical characteristics of silicone by B. cereus bio adhesion favours the adhesion of hydrophilic Lc. lactis on the surface adhered by biofilm. Lc. lactis was able to adhere to silicone surface and produce biofilm obviously exhibited a significant reduction of B. cereus adhered cells up to nine orders of magnitude after 48 h of contact with competitive activity for nutrient and oxygen. This study constitutes a step ahead in developing strategies to prevent microbial colonization of silicone with lactococcal protective biofilm.