THERMAL INACTIVATION OF SEVERAL MYCOBACTERIUM SPP IN MILK BY PASTEURIZATION

The thermal inactivation of Mycobacterium avium, Myco. bovis, Myco. fo rtuitum, Myco. intracellulare and Myco. kansaii in milk at 63.5 degree s C was investigated. Survivors were enumerated after heating for 0, 5 , 10, 15, 20 and 30 min and thermal death curves were constructed for each species. Mycobacterium bovis and Myco. fortuitum were found to ex hibit linear thermal death curves and neither species demonstrated any survival after heating at 63.5 degrees C for 30 min (equivalent to ho lder pasteurization). In contrast, Myco. avium, Myco. intracellulare a nd Myco. Kansasii yielded thermal death curves which exhibited signifi cant 'tailing' and all three strains survived holder pasteurization.