Microbiologie médicale et diagnostic

Evaluation of Mycobacterium bovis Isolated from Cattle in Mexico for Serum Reactivity and Antigen Production Kinetics

Abstract

Juan Manuel Favela-Hernández, Raquel Muñiz Salazar and Gloria Guillermina Guerrero Manriquez

Immunodominant antigens represent a potential tool to develop serological diagnosis in bovine tuberculosis (bTB). Novel antigens from natural acquired Mycobacterium bovis from aerosol infected animals have been identified. However, still it is necessary to define antigen recognition directly from the cattle. Herein, we are reporting an evaluation of M. bovis strains isolated from cattle in Mexico using tubercle bacilli cell growth for serum reactivity and antigen production kinetics (7-21 days). During early, middle and longtime cell growth, we found that there are a set of proteins that in comparison with BCG antigens, mostly reacted toward either pooled or individual serum positive samples obtained directly from animals infected with M. bovis. Interestingly, we found that antigens of 45, 48, 75 and 90 KDa produced at 7 or 21 days are mostly recognized by the serum of infected cattle TST(+) vs. uninfected (TST-). Altogether, the data reported here indicate that in addition to the cell wall factor virulence factors; the antigens mostly recognized and produced during the growth of tubercle bacilli could strengthen diagnostic tests in cattle while discarding BCG cross reactivity.