BapA, A Brucella abortus ADHESIN INVOLVED IN THE ORAL ROUTE OF INFECTION

MERWAISS F; CZIBENER C; UGALDE JE

Puerto Madryn, Chubut, Argentina

Congreso; SAIB 46th Annual Meeting.; 2010

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Brucella abortus is an intracellular pathogen and the causative agent of brucellosis, a worldwide zoonosis important for animal breading and of human health concern. The virulence of Brucella is dependent on the presence of specialized virulence factors that allow the bacteria to invade, persist and replicate within host cells. We used a bioinformatic approach to search for potential proteins that might play a role in bacterial virulence. The search identified a genomic region that harbours four open reading frames, one of which (bapA) has a domain with homology to the intimin of enterohemorragic E. coli, a receptor essential for attachment of this pathogen. Our results indicate that this virulence factor is involved in the adhesion to host cells by probably recognizing and binding a cellular receptor. In an attempt to identify this receptor we produced and purified a recombinant BapA and coupled it to an affinity column. Total HeLa extracts were injected into this column and proteins bound to it eluted with different stringent conditions and subjected to poliacrylamide gel electrophoresis. With this approach we have detected one major differential band that is currently being identified. Additionally, we have infected mice intraperitoneally and orally with wild type and bapA strain. Our results suggest that this adhesin might play a role in the oral route of infection.