Adhesion factors and signaling pathways involved in the interaction between Bacillus cereus and cultured human enterocytes

22- MINNAARD, J.; ROLNY, I.; AND PÉREZ, P. F.

Carlos Paz, Córdoba

Congreso; VI Congreso Argentino de Microbiología General; 2009

Sociedad Argentina de Microbiología General

Factors involved in the interaction of Bacillus cereus with cultured human enterocytes as well as the signaling pathways responsible for the biological effects were investigated. Results demonstrate that bacterial viability is crucial for the association of B. cereus to enterocytes. In a strain dependent manner, treatments with LiCl , proteases and exhaustive washing showed that non-covalent bound structures, proteins and loosely associated material are involved in the interaction. Extracellular factors from strain 2 increased its own association and invasion values and also association of strain B10502.  Calcium depletion increases ability of strains T1 and 2 to invade cells. Bacteria associated in greater extent to undifferentiated enterocytes. Inhibitors of signaling pathways related to phosphorylated (U73122 and wortmannin) lipids were able to abrogate citoskeleton disruption induced by B. cereus. Adhesion of strain T1 decreased in the presence of U73122, wortmannin and when those inhibitors were used together. In contrast, invasion values were diminished only by U73122. Results show that different bacterial structures are related to the interaction of B. cereus with cultured human enterocytes and activation of signaling cascades related to phosphorylated lipids leads to profound modifications on the cytoskeleton that in turn facilitate the invasion of the monolayers through both the apical and the basolateral domains.