Microbiological analysis and sensitivity profile of Staphylococcus spp. in subclinical mastitis of dairy goats

Subclinical mastitis in goats causes economic losses and risks to public health. Given the need for research that shows the most isolated staphylococci species and sensibility tests comparing the resistance between coagulase-negative (CNS) and positive Staphylococcus (CPS) goats with subclinical mastitis, the aim of this study was to identify the microorganisms isolated from milk samples of goats with subclinical mastitis, as well as define the staphylococci species and determine the sensitivity profile of Staphylococcus spp. to antimicrobials. To collect samples, tests were performed for mug of black background and California mastitis test (CMT), collecting milk from CMT positive animals. A total of 226 samples from seven herds of dairy goats was collected and forwarded to the laboratory, where they were seeded for the isolation of the microorganism and implementing the antibiotic sensibility test. Of these, 122 samples had bacterial growth and the most isolated staphylococci species were: S. epidermidis (24.55%), S. lugdunensis (15.40%) and S. intermedius (13.64%). Samples showed increased resistance to antimicrobials: penicillin (81.8%), oxacillin (60.0%) and ampicillin (55.5%). Greater sensitivity to: enrofloxacin (99.1%), erythromycin (98.2%), gentamicin (98.2%) and vancomycin (98.2%) were observed. The S. epidermidis showed higher antimicrobial resistance to amoxicillin and penicillin than S. lugdunensis and S. intermedius. Similar resistance in vitro between CNS and CPS was observed to most antimicrobials. It is important to control the overuse of antibiotics to prevent the emergence of resistant strains.