An infection with Septata intestinalis was diagnosed in a 35-year-old AIDS patient without diarrhoea. The diagnosis was based on morphological examinations of a duodenal biopsy specimen. Serum antibodies were detected reacting with spores of Encephalitozoon cuniculi. Spores of S. intestinalis and E. cuniculi stained with Brown Hopps Gram stain showed a red colour (Gram negative) and not a blue/black colour which was described for microsporidian spores in tissue.
The circulating antibody profiles of rabbits infested or immunized with Sarcoptes scabiei var. canis were compared. Crossed immuno-electrophoretic analysis showed that infested hosts produced serum antibody to 12 proteins (antigens) in an extract made from sarcoptic mite bodies. In contrast, rabbits immunized with an extract made from mite bodies produced antibody to 20 Sarcoptes proteins (antigens). SDS-PAGE/immunoblot analysis revealed that serum from immunized rabbits contained antibodies that bound strongly to proteins of 25 and 39-52 kD that were only barely visualized by antibodies in serum from infested rabbits.