Evaluation of immune responses.
Immune responses were evaluated as production of interferon gamma (IFNγ) in supernatants of peripheral blood cells incubated overnight at 37oC in a 5% CO2 and 95% humidity atmosphere with purified protein derivative from Mycobacterium avium (PPD-A) or M. bovis (PPD-B), or medium alone as negative control (Villarreal-Ramos et al., 2014). Levels of IFNγ were determined by using the Bovigam™ assay (Prionics). Data are shown as mean ± SEM.