Mastite bovina na Ilha de São Luis, MA: freqüência, etiologia e perfil de sensibilidade de bactérias aos antimicrobianos

Abstract

The bovine mastitis causes great economic losses to the dairy herd, interfering with the productivity and quality of milk. The objective of this research was to determine the frequency, etiology and antimicrobial susceptibility profile of bacterial strains isolated from of dairy cows. 217 dairy cows were evaluated of 14 properties located in São Luís, Paço do Lumiar, São José de Ribamar and Raposa, state of Maranhão, using Tamis and California Mastitis Test (CMT). Of 857 rooms mammary evaluated, 27 (3.12%) had clinical mastitis and 215 (25.08%) subclinical mastitis. In samples of reagents to CMT, 69 showed score 1 +, 103 scores 2 + and 43 score 3 +. 242 milk samples positive for clinical and subclinical mastitis were collected and microbiological analysis for the isolation and identification of microorganisms. The profile of antimicrobial susceptibility of strains was estimated by the method of distribution in disks, using the 14 antibiotics agents, using the technique of diffusion discs following. Coagulase positive Staphylococcus (14.46%), coagulase negative Staphylococcus (26.86%) and S. aureus (14.46%), Streptococcus spp. (20.66%), Corynebacterium spp. (4.13%), yeasts (2.48%) and Gram negative bacilli (1.24%) were isolated of samples. There was not microbial growth in 15.70% of the samples. The antibiotics that showed greater efficacy to coagulase negative Staphylococcus, coagulase-positive Staphylococcus and S. aureus were vancomycin (96.0%, 95.9% and 96%), sulfa + trimetropim (92.0%, 77.5% and 96%), bacitracin (89.8%, 94.0% and 92,9%) and gentamicin (72.0%, 71.4% and 92.6%), respectively. The bacitracin (93.4%), vancomycin and amoxicillin (92.6%) were the most effective antimicrobial agents against strains of Streptococcus spp. The coagulase-negative Staphylococcus was the etiologic agent most frequently isolated and showed higher profile of multiresistance in which 32.65% were resistant to more than 8 antimicrobials, simultaneously. The results indicate the need for adoption of measures for prevention and control of mastitis and treatment based on the profile of antimicrobial sensitivity of microorganisms causing disease.