Chronology of Morphological Forms of Mycobacterium bovis Rapid-Growing Strain

The study aimed to examine the changes observed in the morphology of rapid-growing tuberculosis pathogen strain, degree of pathogenicity, sensitized properties, and content of lipids, which depend on the pH of the medium, for 180 inoculations of 1–3 days culture. The reversion of non–acid-resistant forms of Mycobacterium bovis of the rapid-growing strain to bacterial acid-resistant forms occurred because of the following reasons: formation of non–acid-resistant grains in thread-like M. bovis, transformation and fragmentation of non– acid-resistant thread-like forms into acid-resistant rod-shaped bacteria, and output from non–acid-resistant thread-like M. bovis acid-resistant forms. It was found that increasing the number of passages of M. bovis of the rapid-growing strain through the medium at pH 6.7 led to a probable decrease (p<0.05) in the content of total lipids; fractions of phospholipids, triacylglycerols, and sterin ethers; and an increase in the number of diacylglycerols, sterins, and free fatty acids (FFAs). It is established that the decrease in saturated and long-chain fatty acids and the increase in unsaturated and short-chain fatty acids were accompanied by the loss of virulence of mycobacteria. Of the 19 FFAs, nine tended to disappear from the cell wall.