INTERACTION OF ANTIMICROBIAL SUBSTANCES IN BORDETELLA BRONCHISEPTICA

The use of a combined antimicrobial drug based on two or more active substances may be useful for the treatment of mixed bacterial infections in which the pathogens are not susceptible to the individual active pharmaceutical ingredients (API) of the chemotherapeutic agent, for a synergistic antimicrobial effect against particularly resistant strains, or to reduce the risk of emergence or overcoming antibiotic resistance of bacteria. Combined antimicrobial therapy is especially appropriate in mixed infections or when it is necessary to make an empirical choice in a life-threatening situation. The basis for the creation of a combined antimicrobial drug is the study of the interaction of its API with target species of microorganisms. The article presents the results of studying the interaction of various antimicrobial substances, what are active ingredients of combined chemotherapeutic drugs presented on the ukrainian veterinary market, in Bordetella bronchiseptica, that can cause respiratory diseases at a wide range of mammals, including dogs, cats, pigs, cattle, horses and rabbits. The study of antimicrobial interaction was performed using the checkerboard method, based on the minimum inhibitory concentrations (MICs) of each API combination for B. bronchiseptica. The reference test organism Bordetella bronchiseptica ATCC 4617 was used for the study. The results of the study of the interaction of antimicrobial substances showed that the combinations of enrofloxacin and gentamicin, oxytetracycline and colistin, and amoxicillin and colistin cause an additive effect for B. bronchiseptica. A synergistic interaction of the combinations of enrofloxacin and colistin and gentamicin and colistin for B. bronchiseptica was established, which indicates the feasibility of using combined antimicrobial drugs based on them for the treatment of bordetelliosis in animals.