Antimicrobial resistance of bovine mastitis pathogens

Abstract

Inflammation of mammary gland - mastitis - can be caused by various reasons, both physical and microbiological. Mastitis affects physical and technological quality of milk, growth of economic costs and increase in milk production cost, especially due to the use of antimicrobial drugs. The purpose of the research was to study antibacterial resistance of mastitis pathogens in cattle. The studies were carried out in the Oktyabrsky and Kamyshinsky districts, Volgograd region in 2019-2023. 1206 milk samples from Holstein- Friesian cows aged 4-7 years were examined using standard microbiological methods. Antimicrobial susceptibility testing was performed on Mueller - Hinton agar using a modified Kirby - Bauer disc diffusion method. Based on the results of microbiological studies, microbial growth of 984 cultures ( S. aureus , Str. agalactiae , Str. uberis , E. coli , Klebsiella spp. , Pseudomonas aeruginosa , Pasteurella multocida , Trueperella pyogenes and Mycoplasma spp. ) was identified . In the study, multiple resistance to the studied antimicrobial drugs was noted, for example, E. coli had resistance to all 9 drugs; Pseudomonas aeruginosa - to 8; Mycoplasma spp. - to 7; S. aureus , Str. agalactiae , Str. uberis , Klebsiella spp . and Pasteurella multocida - to 6; Trueperella pyogenes to 1 drug. Constant monitoring of resistance of bovine mastitis pathogens to antimicrobial agents contributes to a more effective selection of therapy for clinical mastitis.