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

Detection of antitoxin against thermolabile (LT) enterotoxin of Escherichia coli in porcine sera, by immune haemolysis reactions

Amostras de soros pareadas, coletadas de 69 leitöes recém-nascidos, de diferentes leitegadas, foram examinadas quanto a presença de anticorpos anti-enterotoxina termolábil (LT) de Escherichia coli, pelos testes de imuno hemólise passiva (PIH) e imuno hemólise radial (SRIH). Quinze amostras foram negativas em ambos os testes enquanto 47 näo mostraram nenhum aumento no nível de antitoxina LT. Sete amostras pareadas de soros apresentaram algum aumento no nível de anti-LT. Os resultados negativos obtidos com 15 soros pareados indicam uma provável susceptibilidade dos respectivos leitöes a infecçöes por amostras de E. coli LT+. A diminuiçäo nos níveis de antitoxina LT em muitas das amostras de soros pareados sugere que esses anticorpos foram transmitidos via colostro. Nosso achados mostram que as reaçöes de imuno hemólise podem ser usadas na avaliaçäo da imunidade passiva humoral anti-LT de E. coli em suínos recém-nascidos