Repertoire of antigens and virulence factors of Mycobacterium avium subsp. paratuberculosis

ROMANO MARIA ISABEL; MARIANA VIALE; MARIA LAURA MON; MARIA ALEJANDRA COLOMBATTI OLIVIERI; MALCHIODI; GABRIELA ECHEVERRIA; CLARA ESPITIA

Bucamaranga

Congreso; VI Meeting of the SLAMTB 2012; 2012

Sociedad Latinoamericana de Tuberculosis y otras micobacteriosis

Paratuberculosis (PTB) is caused by Mycobacterium avium Subs., paratuberculosis (MAP). The disease causes granulomatous enteritis mainly in ruminants. The possible relation between Map and the inflammatory process of the human intestine know as Crohn?s disease has promoted studies on the presence of MAP in the human food chain. Blocking the primary stages of the infection, which begins with the binding to the receptors on the host cells and the colonization of the intestinal epithelial mucosa, can be the most effective strategy for the prevention of infections by this bacterium. After colonizing the intestinal epithelial mucosa, the bacterium is phagocytized by local macrophage, where it survives and replicates. It has been shown that MAP proteins capable of binding to components of the extracellular matrix (ECM), such as fibronectin (Fn), are important for the early adhesion of mycobacteria to the epithelial cells of the intestine. It has also been dmostrated that MAP proteins present in the cell wall, in addition to adhesions, may be important antigens.  Objetives, methods and results: In a study of the proteins of the wall of MAP and the culture supernatant with Fn-binding capacity, we identified various adhesions by means of Far Western blot and Surface Plasma Resonance. One of these adhesions, GlnA1, binds to this component of the ECM with a KD of 35uM. Since we evaluated the ability to bind Fn and the antigenic ability of 51 MAP recombinant proteins by multi-antigen printing immunoassay (MAPIA). This technique allowed us to identify new potential adhesions and evaluate the ability of these proteins to react with 43 sera (25 from animals naturally infected with MAP, 10 from control animals from negative herd, and 8 from animals with tuberculosis). The initial evaluation allowed us to select seven antigens (MAP 2513, MAP 1693, MAP 2020, MAP 0038, MAP 1272, MAP 0209 and MAP 0210). A mixture of these antigens reacted mostly with the sera from animals naturally infected with MAP and showed little or no cross-reaction with the sera from healthy animals and animals with tuberculosis.