FEATURES OF BEETLE INFECTION WITH MYCOBACTERIA AND THEIR INFLUENCE ON THE VIABILITY OF THE PATHOGENS

Abstract

The issue of the active spread of tuberculosis throughout the world has been relevant for many decades. Today, the main reason for the spread of the disease is the imperfection of the study of the mechanisms of
mycobacteria activity and the lack of a complete understanding of all the existing ways of introducing the
pathogen into a safe territory. Numerous scientific works of scientists have established that insects are capable of carrying various bacteria in their bodies, including pathogenic microorganisms. This work
presents materials on the ability of the rice weevil to reserve mycobacteria in its body. The purpose of our
study was to find out the ability of beetles to accumulate mycobacteria, to determine the necessary amount of the pathogen to contaminate insects, and to determine their effect on the viability of the pathogen. The
virulent strain of Mycobacterium bovis and its dissociative form (118 passages), beetles of the rice weevil
species (lat. Sitophilus oryzae) were used for the experiment. We infected experimental beetles by keeping
them in wheat grain contaminated with the pathogen for three days in three different variations, followed by
microscopic examination (on the fourth day) of smears of body surface washes and homogenate, which were
stained by the Ziel-Nielsen method. It was established that for the infection of 100% of insects, the required
concentration is 10 mg of mycobacterial suspension per 10 g of grain. It has been proven that after passing
through the organism of the rice weevil, the causative agent remains viable, but its viability decreases. When
counting colony-forming units in the dynamics of the experiment, a decrease of dissociative forms and the
pathogenic strain of M. bovis was observed by 12.3% and 13.6%, respectively. The obtained results make it
possible to expand the existing data on the spread of tuberculosis and to improve measures to prevent the
disease and prevent the introduction of the causative agent of the infection.