Catarina Guimarães Rocha Dourado Lima

Potency against enterotoxemia of a recombinant Clostridium perfringens type D epsilon toxoid in ruminants.

Enterotoxemia, a disease that affects domestic ruminants, is caused mainly by the epsilon toxin from Clostridium perfringens type D. Its eradication is virtually impossible, control and prophylaxis are based on systematic vaccination of herds with epsilon toxoids that are efficient in inducing protective antibody production. The use of recombinant toxins is one of the most promising of these strategies. This work evaluates the potency of a Cl. perfringens type D epsilon toxoid expressed by Escherichia coli administered to goats, sheep, and cattle. The etx gene was cloned into the pET-11a plasmid of E. coli strain BL21 to produce the recombinant toxin. Rabbits (n=8), goats, sheep, and cattle (n=5 for each species) were immunized with 0.2mg of the insoluble recombinant protein fraction to evaluate vaccine potency of the epsilon toxoid studied. Antibody titers were 40, 14.3, 26, and 13.1 IU/mL in the rabbit, goat, sheep, and cattle serum pools, respectively. The epsilon toxoid produced and tested in this work is adequate for immunization of ruminants against enterotoxemia.

Botulismo em ruminantes causado pela ingestão de cama-de-frango

Botulismo e uma intoxicacao causada pela ingestao das toxinas produzidas pelo Clostridium botulinum, que acomete mamiferos e aves. Neste trabalho e descrito um surto de botulismo em ruminantes, ocorrido em duas propriedades localizadas no municipio de Patos, no Estado da Paraiba, Brasil. Em uma das propriedades, de um total de 88 bovinos, 85 (96,6%) vieram a obito. Na segunda, morreram 145 ovinos (96,7%), 233 caprinos (57,8%) e 30 bovinos (96,8%). Os animais acometidos apresentavam paralisia progressiva, dificuldade de locomocao, sialorreia e dispneia. A morte ocorreu entre 24 e 48 horas apos o inicio dos sinais, por parada cardio-respiratoria. Nenhuma alteracao significativa foi observada no exame post-mortem. O diagnostico de botulismo foi confirmado pela demonstracao das toxinas C e D no conteudo intestinal e na cama-de-frango utilizada na alimentacao dos animais, pela tecnica de soroneutralizacao em camundongos.

In vitro evaluation of Clostridium septicum alpha toxoid

Aiming to investigate in vitro alternatives, a test for neutralizing antibody detection using cell culture was developed. This test was more sensitive than previous animal models, allowing for detection of substantially lower alpha toxin and anti-alpha toxin titers. Titers observed during in vivo and in vitro seroneutralization had a correlation of 99.12%, indicating that cell culture is a viable alternative in the evaluation of vaccine potency, screening of vaccinal seeds, and Clostridium septicum alpha toxin titration.

Viabilidade de Tritrichomonas foetus após congelamento com diferentes crioprotetores

The aim of this work was to evaluate the viabilitity of Tritrichomonas foetus cryopreservated with glycerol and dimethilsulphosyde (DMSO) at -196 degrees C. Samples of the protozoa were thaw two days and 6, 12, 18, and 26 months after freezing to be evaluated. In the time analyzed, the freezing was viable in 60% and 90% of freeze samples with glycerol at 10% and DMSO at 12%, respectively.

Produção e caracterização de anticorpos monoclonais contra toxina épsilon de Clostridium perfringens Tipo D

Clostridium perfringens type D is the aetiological agent of enterotoxemia in ruminants. The disease is caused by epsilon toxin characterized by cardiac, pulmonary, kidney and brain edema. Monoclonal antibodies were produced by using myeloma cell line P3-X63-Ag8 653 fused with spleen cells from Balb/c mice, immunized with epsilon toxoid of C. perfringens type D. Six hybrids were established secreting monoclonal antibodies of the IgM class and IgG3 subclass.

Detection of several clostridia by a direct fluorescent antibody test in formalin-fixed, paraffin-embedded tissues

Descreve-se a aplicabilidade de uma tecnica de imunofluorescencia direta, para o diagnostico de mionecroses causadas por clostridios, a partir de tecidos fixados em formol e incluidos em parafina. Essa tecnica pode auxiliar no diagnostico do carbunculo sintomatico e da gangrena gasosa, contribuindo para determinar a real prevalencia dessas doencas no pais.