Inativação de Mycobacterium bovis (espoligotipos SB0120 e SB1033) em leite integral submetido à  pasteurização lenta e rápida em banho Maria

Abstract

AGRADECIMENTOSMycobacterium bovis causes zoonotic tuberculosis disease that affects animals and humans and can cause death, the milk is an important route of disease transmission to humans. The pasteurization of milk is the main measure to break the transmission chain, whose time and temperature parameters were defined by experiments dating from the late nineteenth century, based on thermal resistance of M. bovis and Coxiella burnetti, considered then the most resistant non-spore-forming pathogens that contaminate the milk. In Brazil, there are two approved binomials 62 ° C to 65 ° C for 30 minutes and 72 ° C to 75 ° C for 15 to 20 seconds.However, over the years and the emergence of new technologies (PCR, spoligotyping and other biomolecular techniques) was observed genetic differences intra-species. Thus, this project aims to evaluate and compare the behavior of two spoligotypes of M. bovis (SB0120 and SB1033) compared to the two pasteurization protocols used in the country. To this end, UHT milk was contaminated with these spoligotypes and subjected to two thermal processes in a water bath. The milk was streaked on solid medium Stonebrink-Leslie and colony counting was done after 45 days of incubation at 37 ° C. This experiment showed that there was no difference between the thermal resistances of the two spoligotypes, however it was detected a greater importance of the heating phase in reducing the agent that the maintenance phase of temperature for the two spoligotypes, in both cases.