Abstract
Background:
Antibiotic resistance is a global health problem related to the transmission of bacteria and genes between human and animals. The development of new drugs with antimicrobial activity research is an urgent task of modern science.
Aim:
The article presents data of in vitro and in vivo experiments new pharmaceutical composition based on nisin.
Methods:
The antimicrobial activity was studied on the mastitis pathogens. To identify microorganisms the MALDI-TOF (mass spectrometry) method was performed using. To determine sensitivity, the serial dilution method and the diffusion method were used. On laboratory animals, biochemical, hematological and histological research methods were used. Female nonlinear white laboratory rats were used, which were divided into one control group and three experimental ones.
Results:
“Duration” factor was statistically significant for the following indicators: hemoglobin, hematocrit, leukocytes, lymphocytes, erythrocyte sedimentation rate (ESR) and eosinophils. The “Dose” factor did not show significance for any indicator, which means that the effect was similar regardless of the dose chosen. When analyzing the biochemical indicators, significant differences were found in the “Duration” and “Dose” factors, in the direction of a decrease in the indicators of total protein, globulins, urea and an increase in the concentration of alkaline phosphatase. When conducting histological studies in the first experimental group, it was established that there were no changes in the structural and functional units of the organs. In animals of the second experimental group, the presence of reversible pathological processes of a compensatory nature was noted. More profound changes in the structure of the studied organs were recorded in the third experimental group.
Conclusion:
An in vitro study on cell cultures showed that the pharmacological composition has high antimicrobial activity against isolates from the mammary gland secretion of cows with mastitis. An in vivo study on laboratory animals showed that the developed composition belongs to the IV class of substances "low-hazard substances". Histological examination made it possible to select the safest dose of the pharmacological composition of no more than 500 mg / kg.

Key words: Biochemical parameters, Chronic toxicity, Hematological parameters, Histological studies, Mastitis pathogens