As a result of the studies, it was established that most often pathogenic streptococci are isolated from milk samples from cows with mastitis (28,9 % of cases), Escherichia coli is in second place in terms of isolation – 28,55 % of cases, followed by pathogenic staphylococci – 14,17 % of cases.

   Research has been carried out to isolate an isolate of the coronavirus SARS-CoV-2. As a result, an isolate of the SARS-CoV-2 virus was isolated.

   The article shows the results of the analysis of the incidence of pasteurellosis, the isolation of pasteurellas from samples of biological material, and the selection of strains.

   The passage of potentially pathogenic microorganisms in a diffusion test with dilutions of antibiotics makes it possible to determine the number of contacts of the drug with microorganisms, leading to the emergence of resistant strains, which makes it possible to adjust the scheme of their use to reduce the risk of developing microflora resistance and ensure the effectiveness of treatment. Antimicrobials with the same active substances, but from different manufacturers, may differ in the spectrum of action and the rate of development of microflora resistance to them, which makes it necessary to determine these indicators during registration tests and adjust the instructions for use.

   The article presents the results of the study of changes in hematological parameters and phagocytic activity of white mice blood leukocytes during experimental infection with Clostridium perfringens. The obtained experimental results testify to the multidirectional influence of clostridium infectious load on changes in the blood composition of mice, especially in the early periods of observation; so infection of mice with a dose of 5,0×10⁷ microbial cells/mouse causes a decrease in almost all studied hematological parameters. On the contrary, infection of mice with a dose of 5,0×10⁵ microbial cells/mouse is accompanied by leukocytosis in the early period of observation and erythrocytosis in the late period of observation. The phagocytic activity of leukocytes, i.e. phagocytic index and the degree of completed phagocytosis in blood leukocytes, decreased regardless of the dose of Clostridium perfringens infectious load.

   The article provides data on the use of ERIC and RAPD PCR methods in the genotyping of epizootic strains of Pseudomonas aeruginosa.

   The article presents data on the isolation of the bacteria Bifidobacterium asteroids from the intestines of a zoned bee and the study of their antagonistic activity. As a result of the research, three strains of Bifidobacterium asteroides were isolated and identified: BG9, BG21 and BG24. The identified strains demonstrated significant antagonistic activity against pathogens of bee diseases, such as hafniosis (Hafnia alvei 9760 B-57), European foulbrood (Streptococcus pluton, Melissococcus pluton B-11115) and American foulbrood (Penibacillus alvei B-5247).

   The continuing spread of African swine fever (ASF) outside Africa in the whole world, has heightened awareness of the threat posed by this devastating disease to the global pig industry and food security. Fast and accurate African swine fever virus (ASFV) detection method is very important for ASF prevention. A double antibody sandwich FICA method was optimized and established, and FICA strips (FICAS) were assembled and then evaluated. The sensitivity of the FICAS kit was 0,044 ng/mL. The recoveries ranged from 102,07 % to 108,60 %, and all CVs were below 7 %. The common pigs infectious disease samples, positive samples and healthy control samples did not lead to false negative and false positives. The kit can be stably stored at 37 °C for 7 days without significant decrease in fluorescence value. The prepared FICAS kit is rapid, feasible and effective for testing ASFV within 15 min. This study provides a new method for rapidly screening ASFV infection in pigs industry.

   The article reviews domestic and foreign literature and analyses various methodical protocols of formation of spheroids depending on the type of cultivated cells and their use as a cellular substrate for use in biology, medicine and veterinary science.

   The effect of mesenchymal stem cells of bovine adipose tissue on the microflora causing purulent necrotic lesions of the fingers in cows has been studied. The obtained results of clinical studies indicate that the introduction of mesenchymal adipose tissue stem cells into the treatment regimen for infected finger wounds most effectively reduces the number of microorganisms in pathological foci.

   Mycobacterium bovis cells inactivated with glutaraldehyde (GA) after application to sterile moistened soil retained acid fastness and were visually detected for 15 months, although their number decreased due to the restoration of viability in the form of non-acid-fast (NAF) cell wall deficient (CWD) forms. By the 21st month, these forms turned into inconspicuous spore-like forms. For 21 months, in all cases, NAF CWD M. bovis was isolated from contaminated soil when sowing a soil suspension with pre-incubation in the MycCel DW growth stimulant and without it. The isolates weakly induced hypersensitivity to tuberculins, were resistant to most natural antibiotics, had increased resistance to GA and resistance to polyhexamethylene guanidine. It is assumed that the discovered phenomenon leads to the formation of natural foci of infection, and may play a role in the induction of reactions to tuberculin in cattle.

   The article describes the process of creating a disinfectant based on stabilized hydrogen peroxide, its antimicrobial activity and toxicological properties have been studied.

   The article presents the results of a study of an environmentally friendly disinfectant based on stabilized hydrogen peroxide. Organic acids and modified phosphonic acid were used as stabilizers. The corrosive properties, stability of the product during long-term storage and its toxicological characteristics are described. The average lethal dose (LD50) of the disinfectant after intragastric administration is 3900 mg/kg, which corresponds to the 3rd hazard class according to GOST 12.1.007-76.