Clostridium perfringens α and ß recombinant toxoids in equine immunization / Toxóides recombinantes α e ß de Clostridium perfringens na imunização de equinos

Clostridium perfringens is considered one of the main causative agents of superacute enterocolitis, usually fatal in the equine species, due to the action of the ß toxin, and is responsible for causing severe myonecrosis, by the action of the α toxin. The great importance of this agent in the equine economy is due to high mortality and lack of vaccines, which are the main form of prevention, which guarantee the immunization of this animal species. The aim of this study was to evaluate three different concentrations (100, 200 and 400µg) of C. perfringens α and ß recombinant toxoids in equine immunization and to compare with a group vaccinated with a commercial toxoid. The commercial vaccine was not able to stimulate an immune response and the recombinant vaccine was able to induce satisfactory humoral immune response in vaccinated horses, proving to be an alternative prophylactic for C. perfringens infection.(AU)

Clostridium perfringens é considerado um dos principais agentes causadores de enterocolites superagudas, geralmente fatais na espécie equina, devido à ação da toxina ß, além de ser responsável por causar quadros graves de mionecrose, pela ação da toxina α. A grande importância desses agentes na equinocultura, deve-se a elevada mortalidade e a inexistência de vacinas, principal forma de prevenção, que garantam a imunização dessa espécie animal. O objetivo deste trabalho foi avaliar três diferentes concentrações (100, 200 e 400µg) dos toxóides recombinantes α e ß de C. perfringens na imunização de equinos, bem como comparar com um grupo vacinado com um toxóide comercial. A vacina comercial não se mostrou capaz de estimular uma resposta imune e a vacina recombinante foi capaz de induzir resposta imune humoral satisfatória em equinos vacinados, provando ser uma alternativa profilática para infecção por C. Perfringens.(AU)

Mapping of the continuous epitopes displayed on the Clostridium perfringens type D epsilon-toxin

Abstract The epsilon toxin, produced by Clostridium perfringens, is responsible for enterotoxemia in ruminants and is a potential bioterrorism agent. In the present study, 15 regions of the toxin were recognized by antibodies present in the serum, with different immunodominance scales, and may be antigen determinants that can be used to formulate subunit vaccines.

Avaliaçäo de vacinas contra Clostridium perfringens tipos C e D / Evaluation of vaccines against Clostridium perfringens type C and D

Determinou-se a eficiência de sete vacinas comerciais contra clostridioses, que continham toxóides de Clostridium perfringens tipos C e/ou D, pelo teste de soroneutralizaçäo em camundongos a partir do "pool" de soros de coelhos imunizados. Seis vacinas produzidas no Brasil foram ineficientes em estimular níveis sorológicos de beta e épsilon antitoxinas compatíveis com os níveis de teste recomendados para controle destes produtos. Uma vacina importada apresentou títulos de anticorpos séricos superiores aos níveis mínimos exigidos de 10 e 5UI/ml para as toxinas beta e épsilon, produzidas por C. perfringens tipos C e D, respectivamente. Como controle dos testes empregou-se um toxóide bivalente padräo. Quatro dos seis toxóides de origem nacional, quando testados em caprinos, näo apresentaram níveis de antitoxinas detectáveis com os níveis de testes de L+ e L+/10 para beta e épsilon toxinas, respectivamente

Use of an indirect haemagglutination test, for the detection of Clostridium perfringens type A enterotoxin

An indirect haemagglutination (IH) test is described for the detection of Clostridium perfringens type A enterotoxin, produced by strains isolated from human cases of food poisoning and from contaminated food. Though no strict relationship could be observed between titers in the IH test and the time it took mice to die from the intravenous inoculation of mice (IIM), results of the supernatants examined by both methods demonstrated that the IH test was more sensitive than the ILM one. No unspecific reaction was obtanined int he IH wirh a negative control and the inhibitions of the IH and IIM tests by specific antiserum against C. perfringens enterotoxin showed that the IH test is very spcific. The IH assay is recommended for its sensitivity and easy performance by less-equipped laboratories, by these and other data

Immune response to clostridial vaccines in sheep with special reference to passively acquired cl welchii types B and D antitoxin in lambs

Field trials in sheep and lambs were carried out with Cl. welchii type B vaccine used alone or in combination with Cl. welchii type D. Effective responses were obtained and there was no observable interference when antigens were combined nor did passive Beta antitoxine or epsilon antitoxin prevent response to Cl. welchii type B toxoid or Cl. welchii type D toxoid in lambs. Moreover complete passive protection against lamb dysentery and pulpy kidney diseases occurred up to 8 weeks of age in lambs born to ewes inoculated with the routine dose of 2 ml. Cl. welchii type B or Cl. welchii type D before lambing, whether this was a booster dose or the second dose of the primary series. In a small selected group 30% were still protected at 16 weeks of age. Doubling the dose of vaccine significantly raised the titres of ewes at parturition and also increased the percentage of passively protected lambs to 50%

Especificidad frente a estreptococos grupo A, C y G de la prueba de "CAMP reversa" en identificación de Clostridium perfrigens / Specificity of the reverse CAMP test with Streptococcus groups A, C and G for the identification of Clostridium perfringens

Se estudió la especifidad de la prueba de "CAMP reversa" para la identificación de Clostridium perfringens en relación a la posible existencia de reacciones cruzadas frente a estreptococos grupos A, C y G. Noventa y ocho cepas de Clostridium se enfrentaron a 10 cepas de S. agalactiae, 10 cepas de S. pyogenes, 2 cepas de Streptococcus grupo C y 1 del grupo G. Todas las cepas de S. agalactiae ensayadas permitieron poner de manifiesto una reacción de "CAMP reversa" positiva al enfrentarlas a cepas de C. perfringens. No se observaron reacciones cruzadas de C. perfringens frente a los Streptococcus de los grupos A, C y G probados. La prueba de "CAMP reversa" fue específica para todas las cepas de C. perfringens ensayadas