VOGES-PROSKAUER AND COAGULASE TESTS TO THE LABORATORIAL DIAGNOSTIC OF Staphylococcus aureus INCLUDED IN THE EPIDEMIOLOGY OF BOVINE MASTITIS / UTILIZAÇÃO DO TESTE DE VOGES-PROSKAUER E DA COAGULASE PARA O DIAGNÓSTICO LABORATORIAL DE Staphylococcus aureus ENVOLVIDOS NA EPIDEMIOLOGIA DA MASTITE BOVINA

ABSTRACT

Diagnostic characteristics of acetoin production to the Staphylococcus aureus isolated from milk of mammary quarters of cows with mastitis, orifices of teats and mouthpieces of the liners were studied, in agreement to different coagulation grades presented by strains in the tube coagulase test with rabbit plasma and different rain levels in the environment of the herd. The production of acetoin and the coagulase test were performed after growth on blood agar base supplemented with sheep blood, Gram staining and catalase production. All strains were confirmed by molecular identification at species level by species-specific PCR. Among 329 samples identified, 167 were isolated from milk, 117 from teat orifices and 45 from mouthpieces of the liners. Among these samples, 85.0%, 71.1% and 69.2% strains originated from the milk, mouthpieces and orifices, respectively, presented whole coagulation in the coagulase test. Reduced specificities were obtained to the acetoin production to different coagulation grades on the few rains period as well as on the many rains period. Sensitivities to the acetoin production were higher on the few rains period to all sources and coagulation grades, except to strains from orifices with incomplete coagulation and strains from mouthpieces with complete coagulation. It is recommended the acetoin production test how a good diagnostic strategy to the S. au

RESUMO

Estudaram-se as características diagnósticas do teste de Voges-Proskauer (VP) na identificação de Staphylococcus aureus isolados de leite de quartos mamários de vacas com mastite, óstios dos tetos e insufladores dos conjuntos de ordenha, perante diferentes graus de coagulação apresentados pelas cepas na prova de coagulase lenta com plasma de coelho e com distintos níveis de chuvas ocorridas na região da propriedade à qual os animais pertenciam. Os testes de VP e de coagulase foram realizados após o isolamento das amostras bacterianas em ágar sangue, visualização de lâminas após a realização da coloração de Gram e a verificação da produção de catalase. Todas as cepas isoladas foram confirmadas por meio da amplificação de fragmentos de DNA cromossômico específico de S. aureus. Identificou-se um total de 329 amostras como S. aureus, das quais 167 isoladas a partir do leite, 117 originaram-se de óstios e 45 de insufladores dos conjuntos de ordenha. Dentre as amostras isoladas, 85,0%, 71,1% e 69,2% de S. aureus que se originaram de leite, insufladores e óstios, respectivamente, apresentaram coagulação completa à prova de coagulase. Encontraram-se especificidades reduzidas para o teste de VP, para os diferentes graus de coagulação identificados, tanto no período com menos chuvas como no de maiores níveis pluviométricos. As sensibilidades diagnósticas identificadas para o teste de VP