Characterization of microbiota in subclinical mastitis and antimicrobial susceptibility profile of pathogens isolated in dairy farms of family farming

Abstract

Mastitis is the main disease for the dairy cattle. Negatively impacts the milk production chain by decreased of production and by lower industrial yield of dairy products. It is still a public health problem because it can be caused by micro-organisms that produce thermostable enterotoxin causing food poisoning. This study aims to evaluate the presence of subclinical mastitis in dairy farms classified as family farming, located in the municipality of Bofete - SP. Milk samples will be obtained from all lactation cows from each of the 10 properties included in the study according to the interest of their owners. Initially will proceed cleaning and disinfecting the udder and drying with paper towels, conducting the California Mastitis Test - CMT, obtaining milk samples in sterile bottles, to the positive test from the score 1+ reaction. Samples are maintained under refrigeration temperature during transportation until arrival in the laboratory, where they are immediately cultured on blood agar bovine 5% and MacConkey agar media and incubation at 37 ° C for 24 to 72 hours and evaluation of the microbial growth every 24 hours. Each microorganism isolated will be characterized phenotypically according to the features of colonies, such as size, pigment production and hemolysis and morphology by Gram technique and then pricked out to tubes containded brain heart infusion (BHI) to obtain inoculum for performing biochemical evidence for gender and characterization of microbial species, and also antibiogram, and incubating the plates at 37° for 24 hours. It will be considered as positive in the microbiological examination milk samples with isolation of three or more colonies of the same pathogen, except in cases of Staphylococcus aureus, which will be considered even with isolation in a colony. In the case of isolation of three or more different microorganisms, samples will be considered contaminated and will not be part of the analysis. The results will be statistically analyzed by comparing the frequency of isolation of different pathogens between properties and also according to the profile of sensitivity and resistance to various antibiotics used in the antibiogram. (AU)