Direct ABC Immunohistochemistry to Encephalitozoon Cuniculi

Abstract

Among the sera from 9 rabbits spontaneously infected with Encephalitozoon cuniculi, a serum which revealed a high titer for E. cuniculi by indirect protein A-gold (IPAG) immunohistochemistry and reacted with the outer layer of the shell of E. cuniculi spores on immunoelectron microscopical examination, was biotinylated. The biotinylated rabbit anti-E. cuniculi IgG reacted immunohistochemically with E. cuniculi, but not with other protozoa tested, namely Neospora caninum, Toxoplasma gondii and sarcocystis. The direct avidin-biotin-peroxidase complex (ABC) immunohistochemistry using biotinylated rabbit anti-E. cuniculi IgG in this study is a useful tool for the diagnosis and study of encephalitozoonosis.