UNIQUE PROPERTIES OF CELL WALL DEFICIENT MYCOBACTERIA TUBERCULOSIS ISOLATED FROM ULTRAPASTEURIZED MILK

Abstract

The DNA of Mycobacterium tuberculosis (MBT) was found in the milk of cows that did not reacted to tuberculin. After 10 hours of warming up at 98 °С cell wall deficiency (CWD) mycobacterium tuberculosis was isolated from 50% of samples of such milk. Strains of CWD MBT withstood 5 hour warming up at 98 °С. The morphology of cells naturally changed during warming, their acid-fastness increased up to the appearance of completely acid-fast cells. Sowing of warmed suspensions on a special nutrient medium in all cases gave growth of CWD MBT which did not differ from the initial strains, which confirms the unique thermal stability of MBT and indicates that even such extreme thermal exposure does not solve the problem of biosafety of milk.