The article presents the results of allergic and bacteriological studies of cattle from a tuberculosis-free farm. The presence of cattle reacting to an allergen from atypical mycobacteria was established in three allergic simultaneous tests during 2019–2020. Based on the results obtained, the causative agent of tuberculosis and atypical mycobacteria were not isolated during the bacteriological examination of a biological material from animals slaughtered for diagnostic purposes (n = 17), as well as soil (n = 5) and straw (n = 3) samples. However, microorganisms of the genera Nocardia (n = 2), Rhodococcus (n = 10), and Actinomyces (n = 5) were isolated from the biomaterial according to the results of microscopy, culture and biochemical tests. These microorganisms were also isolated from the soil and straw samples. Short-term non-specific reactions in cattle to mycobacterial allergens were due to the persistence and circulation of the aforementioned microorganisms closely related to mycobacteria. It was determined that the genera Nocardia and Rhodococcus are sensitive to the 1.0%, 2.0%, 3.0% solutions of glutaraldehyde, formaldehyde and sodium hydroxide. Thus, it is necessary to take into account the epizootic situation as to the presence of nocardioform microorganisms in the herd during routine allergic studies, as well as in case of differentiation between specific reactions and paraallergic and pseudoallergic ones. It is necessary to carry out comprehensive systematic studies of livestock and feed quality assessment. For the purpose of disinfection, glutaraldehyde and formaldehyde at a concentration of 1.0% are effective in destroying microorganisms of the genera Nocardia and Rhodococcus with 3-hour exposure or more.

The article presents the results of studying the effect of siderophores and iron on the isolation of Mycobacterium bovis from pathological material. It has been established that the simultaneous presence of iron and siderophore from M. phlei in the nutrient medium makes it possible to detect the growth of M. bovis from pathological material 6–8 days earlier; ensures the growth of more colonies and bacterial mass. The presence of heterologous to mycobacteria siderophore (from Nocardia spp.) in the medium reduces the elective (growth) properties of the medium. Siderophores found in the culture filtrate or alcoholic extract of M. phlei can be valuable additives to culture media for the accelerated isolation of M. bovis from pathological material

Національний науковий центр «Інститут експериментальної і клінічної ветеринарної медицини» ПСЕВДОАЛЕРГІЧНІ РЕАКЦІЇ НА ТУБЕРКУЛІН У ВЕЛИКОЇ РОГАТОЇ ХУДОБИ У статті наведені результати епізоотологічних, клінічних, алергічних, патологоанатомічних та бактеріологічних досліджень великої рогатої худоби на туберкульоз у двох благополучних щодо цього захворювання господарствах різних областей України. Установлено, що сенсибілізація до туберкуліну для ссавців була обумовлена наявністю у тварин дикроцеліозної та ехінококозної інвазії, а також мікроміцетами роду Aspergillus mich. За результатами проведених досліджень діагноз на туберкульоз було спростовано.

The purpose of the work was to study the resistance formation in mycobacteria at multiple passages in the presence of the disinfectant “Dezaktin”, to compare the critical concentrations of “Dezaktin” at repeated and single exposure, as well as depending on the phase of growth of the seed. Under the conditions of the constant effect of “Dezaktin” on mycobacteria, it has been established that the mechanisms of resistance formation in pathogens and saprophytes have different paths. The adaptive response of pathogens of tuberculosis and paratuberculosis to adverse conditions in vitro is similar to the process that occurs in vivo and was characterized by transformation into dormant and CWD-forms. The mechanism of resistance in M. phlei to “Dezactin” consisted in the formation of heteromorphic populations with a partial or complete loss of acid resistance, thickening of the cell wall, and an increase in adhesive and hydrophobic properties. M. phlei had the highest biocide resistance, and MAP among pathogenic cultures. After 13 consecutive passages, the critical concentration of “Dezactin” in the medium for M. bovis and M. avium increased 100 times, for MAP — 7, for M. phlei — 1.4 times. The research results allow us to conclude that the processes of adaptation of pathogenic and saprophytic mycobacteria to the negative effects of the environment have different paths, which, in our opinion, is due to the evolutionary niche of their existence, namely, the first group are intracellular parasites, and others are environmental mycobacteria

The results of allergic, bacteriological and biochemical studies in the diagnosis of mycobacterial infections of mammals and birds in the zoo of the municipal enterprise «T. H. Shevchenko park of Culture and Rest» Dnipro city are described. Comprehensive epizootic research was aimed at the exclusion of dangerous pathogenic mycobacteria. Zoological zones of pathogenic mycobacteria were not recorded in the environment and in animal organisms, but in the ground of enclosures and faeces we identified three cultures of acid-fast microorganisms, one of them was identified as M. flavescens, indicating the circulations of mycobacterial agents in internal and external environment of animal biotope of zoo.