[Virulence of Mycobacterium avium and Mycobacterium intracellulare in pigs during experimental and spontaneous infection].

The virulence of M. avium and M. intracellulare was studied in 16 experimentally infected pigs and on 174 animals coming from herds spontaneously infected with the mentioned Mycobacterium species. The result of the patho-anatomic examination and cultivation from samples of lymph nodes, organs, muscles, and excrements proved a higher virulence of M. avium to experimentally and spontaneously infected pigs, as compared with M. intracellulare. The strains of M. avium and M. intracellulare sensibilized all pigs to aviary tuberculin within 80 days from peroral and intranasal infection. Patho-anatomic changes in pigs spontaneously infected with M. avium were proved in 10% of the animals that showed a negative reaction to aviary tuberculin.