Factores que afectan la susceptibilidad antibiótica de staphylococcus aureus aislado de mastitis bovina

Abstract

The main goal of this research project is to establish the relationship between different factors of the milking cow (lactation number and time) and the therapeutic and preventive management of Bovine Mastitis (use of mastitis and laboratory records in therapeutic decisions) on the antibiotic susceptibility of Staphylococcus aureus. For this purpose, 218 raw milk samples were analyzed from which 122 were isolated of S. aureus from 19 cattle herds in the provinces of Azuay and Cañar. In order to determine mastitis and antimicrobial susceptibility we conducted the California mastitis Test (CMT), microbiological culture, and antibiogram with plaque sensitivity discs. The antibiotics for which sensitivity was higher were streptomycin 90.98%, amoxicillin and clavulanic acid 87.70%, penicillin 76.23%, cloxacillin 75.41%, and kanamycin 71.31%. Conversely, the antibiotics with transcendental resistance were erythromycin 36.07%, tetracycline 34.43%, penicillin 23.77% and cephalexin 22.95%. An increased risk of bacterial resistance was observed when lactation time is prolonged. On the other hand, there is no relation of preventive and therapeutic management with the formation of antibiotic-resistant strains.