In vitro susceptibilities of the Microsporidia Encephalitozoon cuniculi, Encephalitozoon hellem, and Encephalitozoon intestinalis to albendazole and its sulfoxide and sulfone metabolites

In vitro comparisons demonstrated that the efficacy of albendazole, albenda zole-sulfoxide, and albendazole-sulfone against pathogenic Encephalitozoon species was proportional to the degree of oxidation at a concentration of > 10(-3) mu g/ml. Furthermore, at a concentration of <10(-2) mu g/ml, benzimi dazoles were more effective against Encephalitozoon cuniculi and Encephalit ozoon hellem than against Encephalitozoon intestinalis.