Mycobacteria isolated from nasal secretions of tuberculin test reactor cattle.

Nasal secretions of 103 Holstein cows from a tuberculosis-infected herd in Argentina were bacteriologically cultured for mycobacteria. Mycobacterium bovis was isolated in 8.7% of the cultures. This method was useful for the detection of active tuberculosis with open lesions. Other mycobacteria, most of which grew rapidly on culture media, were isolated in 32% of the cultures and were of little importance as sensitizing agents to mammalian tuberculin in experimental studies in guinea pigs.