Epidemiological and clinical aspects of the first outbreak of bovine mastitis caused by Prototheca zopfii in Goiás State, Brazil.

The purpose of this survey was to describe the occurrence of bovine mastitis caused by Prototheca zopfii in Goiás State, Brazil. Samples of milk, environment and udder were taken from a herd of 120 Holstein cows. Sabourauds dextrose agar plates were incubated under aerobic conditions at 37 degrees C/96 h, for microbiological analysis. Somatic cell count and milk composition were also determined. Histological sections from two udders were stained with HE and PAS. Prototheca zopfii was identified in six cows whose milk had a watery appearance. They also showed a pronounced decrease in milk yield, fat and lactose. Pronounced infiltration of mononuclear cells, atrophy of alveoli and fibrosis were observed. The presence of this agent in other herds in the State is highly likely.

Diagnosis of clinical bovine mastitis by fine needle aspiration followed by staining and scanning electron microscopy in a Prototheca zopfii outbreak.

Biopsy by fine needle aspiration together with microbiological examination and scanning electron microscopy were evaluated in diagnosis of clinical bovine mastitis in a Prototheca zopfii outbreak. Fine needle aspiration was performed in 21 mammary quarters from ten Holstein cows presenting clinical mastitis caused by P. zopfii. The algae were previously identified in the microbiological examination of milk collected from these cows. Material aspirated from these 21 mammary glands was submitted to cytological staining (Gram, Giemsa and/or Shor staining). Fine needle aspiration enabled cytological identification of the algae in these 21 mammary glands, from which P. zopfii was isolated in the milk. Simultaneously, five mammary fragments collected by fine needle aspiration from these 21 mammary glands presenting clinical mastitis were also submitted to microbiological examination. P. zopfii was also isolated from these five fragments. Scanning electron microscopy technique also identified three of these five P zopfii strains isolated from mammary fragments collected by cytological aspiration. These results suggest that fine needle aspiration may be an alternative method for the diagnosis of clinical mastitis.

Etiologia e suscetibilidade a antimicrobianos dos agentes da mastite bovina isolados na região de Pirassununga- SP-Brasil / Etiology and susceptibility in vitro of the bovine mastitis agents isolated from cattle in the Region of Pirassununga (SP)-Brazil

No período de setembro a novembro de 2000, 543 amostras de leite cru foram analisadas na Universidade de São Paulo-Pirassununga, com o objetivo de conhecer a etiologia e a suscetibilidade in vitro dos agentes da mastite infecciosa bovina, além de estabelecer uma relação entre os agentes identificados e a forma de apresentação da enfermidade. Os microrganismos foram clutivados em ágar sangue de carneiro e identificados por suas características macroscópicas, microscópicas e bioquímicas. Os antibiogramas foram realizados em ágar Mueller Hinton, método de difusão de disco. Os agentes isolados foram: Corynebacterium spp, em 51,4 por cento das amostras; Staphylococcus spp, em 40,3 por cento (71,9 por cento coagulase positiva); Streptococcus spp, em 17,5 por cento (desses, 63,8 por cento eram Streptococcus agalactiae); e ainda, Nocardia spp, leveduras e gram-negativos (50,0 por cento eram Escherichia coli). Foram isoladas 603 cepas, observando-se o predomínio de agentes contagiosos (94,5 por cento sendo 49,0 por cento Corynebacterium spp). Entre os ambientais houve predomínio de Streptococcus uberis (69,7 por cento). Staphylococcus spp, Streptococcus spp, Nocardia spp e leveduras estavam mais associados à mastite subclínica, enquanto Corynebacterium spp ao quadro de animais portadores e gram-negativos à mastite clínica. Entre os agentes avaliados, as cepas de Corynebacterium spp apresentaram a maior suscetibilidade.