Qualidade do leite, mastite e sensibilidade a antimicrobianos em unidades de produção de leite com altas contagens de células somáticas

Abstract

Considering the complexity of related factors to milk quality and mastitis control, it was aimed to evaluate the dynamic of breast infection and the sensitivity profile of the isolated agents from refrigerated milk in relation to mastitis index and their etiology on six unites of Milk Production (UMP) with high level of Somatic Cell Counts (SCC). During three visits between a 20 days interval were conducted an assessment of clinic mastitis cases and milk samples of those infections were collected to isolation, identification and sensitivity trials. The totalities of each herd were represented by some samples of milk cooling tanks to different analysis: milk composition, somatic cell counts, total bacterial count, antibiotic residues, stability to ethanol, isolation microbial agents’ identification and in vitro susceptibility. Between all the proprieties studied the incidence of the mastitis clinic was 0 to 24%, whereas the prevalence was 2,9% to 36%. Among 83 mastitis mammary quarters were isolate 107 bacterial agents in 74 samples and the isolation of fungus came from 27 samples. The main bacterial agents isolated were Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli. Others bacterial also showed a significant isolates were Klebsiella spp. and Pseudomonas spp. The bacterial agents isolated from milk cooling tanks were consistent with the bacterial agents isolated from mastitis cases. However it was a soft divergence between the sensitivity of the milk from affected cows and the milk cooling tanks. Antimicrobial with major in vitro susceptibility from bacterial agents from mastitis cows was enrofloxacin and doxycycline (100%), followed by cefalotin (99,1%); and the isolation from the tanks were: danofloxacin (100%), enrofloxacin (85,2%) and gentamicin (74,1%). The Formulations with higher resistance front to isolated from the mastitis cases was penicillin G associated with novobiocin (53,3%), amoxicillin (49,5%) and ampicillin(42,1%) and compared to isolated from tanks the higher resistances were ampicillin (74,1%), oxacillin (74,1%) and amoxicillin (66,7%). Presence of multiples resistances could be related to indiscriminate use of antibiotics for the treatment of various diseases including mastitis.