Antimicrobial susceptibility of mastitis pathogens of dairy cows in Ukraine

Abstract

Mastitis is one of the most common diseases on dairy farms. It causes significant economic damage associated with the cost of treating sick cows, reduced milk yield and quality indicators of dairy products, and the risk of premature culling of animals. Treatment of cows with mastitis on dairy farms is carried out mainly with antimicrobial drugs, which are usually used without a preliminary test to identify the causative agent of the disease and determine its sensitivity to antimicrobial substances, which is an important part of the effectiveness of therapy. Increasing the resistance of bacteria to antimicrobial substances poses a threat not only to the animal but also to humans, as a consumer of dairy products. The availability of data on the sensitivity of mastitis pathogens to antimicrobial drugs makes it possible for veterinary doctors to choose the most effective antibiotic for treating animals with the shortest duration of treatment. The presented results of studies of breast secret samples taken from cows indicate that in 57.5% of cases, contagious pathogens of mastitis were identified. In particular, Streptococcus agalactiae made 24.1%, Staphylococcus aureus – 18.4%, Corynebacterium spp. – 7.2%, Streptococcus dysgalactiae– 5.6%, Streptococcus uberis – 2.2%. Environmental pathogens accounted for 42.5% of the total number of isolated isolates, among which Streptococci represented gram-positive microflora at 11.5 Streptococcuscus spp. (6.2% Streptococcuscus parauberis (4.4% Streptococcuscus Bovis (0.9%) and Staphylococcus spp. – 10.3%. Gram-negative microflora is 20.6%, among which the largest percentage belongs to E. coli – 8.4% and Klebsiella pneumonia – 1.9%. Mastitis caused by yeast accounted for 1.4% of all diagnosed pathogens. Antimicrobial sensitivity was evaluated using the disk diffusion method (Kirby-Bauer). According to the results of determining the sensitivity of mastitis pathogens to antimicrobial substances, it was found that the highest sensitivity of the isolated isolates was to Ceftiofur, Amoxicillin/clavulanic acid, Rifampicin, Amoxicillin, Gentamicin, Ampicillin, Bacitracin, Cephalexin, Cloxacillin, Enrofloxacin, Trimethoprim/sulfamethoxazole, Oxytetracycline, Lincomycin. The least sensitive – to Spiramycin, Tylosin, streptomycin, neomycin, Marbofloxacin, Tilmicosin, and Danofloxacin.