RESUMOO potencial probiótico in vitro de 12 amostras de bactérias ácido-láticas (11 Lactobacillus spp. e uma Weissella paramesenteroides), isoladas de queijo-de-minas artesanal da Serra da Canastra, foi investigado. Essas amostras foram caracterizadas in vitro quanto à susceptibilidade a antimicrobianos, antagonismo contra microrganismos de referência patogênicos e não patogênicos e sensibilidade a pH gástrico e sais biliares. (Gilliland, 1985).

The most acceptable criteria for diagnosing bovine intramammary infections include results of bacteriological culture and measures of inflammation. Therefore, information on the diagnostic characteristics of the procedures used to identify infected quarters is required. Thus, this study was designed to evaluate a set of criteria to classify the infectious status of an udder at the quarter (single and duplicate milk samples) and cow (composite milk sample) levels, and to compare the infectious status with somatic cell counts (SCCs) of the samples. Here, the SCC thresholds determined by receiver operating characteristic curve analysis had a higher Youden index using mammary quarter duplicate milk samples as the gold standard for testing compared with single quarter and composite milk samples, especially for samples for which at least one of the duplicates was microbiologically positive, regardless of the mastitis pathogen isolated. The kappa coefficient for bacteriological results of the single quarter milk samples (single S1 and S2) was 0.85+0.019, indicating that single quarter milk sampling can be useful in mastitis control programs. Therefore, the use of composite milk samples to detect mastitis pathogens may be limited to the detection of major pathogens, given their predictive values. Thus, our findings suggest that the milk SCCs and microbiological examinations, although regarded as the most reliable indicators of ongoing mastitis, should be used in an integrated manner in mastitis control programs. Furthermore, the accuracy of single, duplicate and composite microbiological analyses to diagnosis mastitis should be considered for its implications in mastitis control strategies.INDEX TERMS: Somatic cell count, mastitis, intramammary infection, sensitivity, specificity, udder health status, dairy cow.

Staphylococcus aureus is one of the pathogens most frequently isolated from cases of mastitis worldwide. To decrease the effect of S. aureus mastitis in dairy farming, alternative strategies for controlling mastitis are needed that depend on a better knowledge of cowto-cow variations in S. aureus antibody production. The present study sought to explore the diversity of S. aureus antibodies produced by dairy cows with a distinct mastitis history and vaccinated with a polyvalent mastitis vaccine. We obtained protein extracts from S. aureus isolates derived from persistent subclinical mastitis. Proteins were fractionated using 2-dimensional gel electrophoresis and Western blotting. Then, Western blotting membranes were exposed to sera from 24 dairy cows that had been divided into the following groups: vaccinated dairy cows that were infected with S. aureus, further subdivided according to whether they (a) remained infected by S. aureus or (b) recovered from the intramammary infection; unvaccinated dairy cows infected with S. aureus; and vaccinated healthy dairy cows with no history of S. aureus mastitis. Proteins found to be reactive by Western blot were identified by mass spectrometry (MALDI/TOF-TOF). Our most important finding was that F 0 F 1 ATP synthase subunit α, succinyl-diaminopimelate desuccinylase, and cysteinyl-tRNA synthetase were potential candidate proteins for the prevention of S. aureus mastitis. This study strengthens the notion that variations among animals should not be ignored and shows that the heterogeneity of antibody production against anti-staphylococcal antigens in animals may enable the identification of new immunotherapy targets.

RESUMOAmostras de queijo de minas artesanal foram coletadas em 18 queijarias localizadas em propriedades rurais da região da Serra da Canastra, Minas Gerais, com o objetivo de avaliar a influência da altitude sobre a população de bactérias acidolácticas. As queijarias estavam distribuídas nas altitudes de 600 a 900m, 900 a 1000m e mais de 1000m. Observaram-se populações mais elevadas de bactérias acidolácticas nas amostras de queijo da altitude de 600 a 900m. Lactobacillus rhamnosus, Lactobacillus casei e Lactobacillus plantarum foram os principais microrganismos isolados e identificados por PCR ARDRA 16S-23S rDNA, além de Enterococcus spp., Lactococcus spp. e outras espécies de Lactobacillus. Sugere-se que estas espécies estejam adaptadas ao ambiente de produção do queijo de minas artesanal produzido na região, o que resultaria em características sensoriais próprias do produto. Palavras-chave: queijo, altitude, bactérias acidolácticas, 16S-23S rDNA ABSTRACT Samples of minas artisanal cheese were collected in 18 small

A mastite bovina é a inflamação da glândula mamária que ocasiona grandes perdas na produção leiteira. Portanto, objetivou-se avaliar a prevalência, agentes causadores e fatores relacionados às práticas de manejo e características de produção determinantes de mastite clínica em 44 propriedades leiteiras de ViçosaMG. Em 617 vacas, a mastite clínica foi determinada por meio de exame clínico da glândula mamária e teste da caneca. Amostras de leite dos quartos mamários com mastite clínica foram submetidas à exames microbiológicos. Um questionário estruturado foi aplicado para determinar os fatores de risco à mastite. A prevalência de mastite clínica nos rebanhos foi de 4,8%. Os agentes etiológicos mais isolados foram Staphylococcus aureus (29,73%), Streptococcus agalactiae (16,21%), Escherichia coli (13,51%) e Leveduras (13,51%). O grande número de animais em lactação por propriedade, falta de sanidade do rebanho, falta de higiene do ambiente e práticas inadequadas de tratamento de vaca seca tiveram associação significativa (p < 0,05) com a prevalência de mastite clínica. Portanto, os manejos ambiental e animal devem ser revistos para auxiliar na diminuição de casos de mastite em rebanhos de Viçosa (MG).