VITTAFORMA-CORNEAE N-COMB FOR THE HUMAN MICROSPORIDIUM NOSEMA-CORNEUMSHADDUCK, MECCOLI, DAVIS AND FONT, 1990, BASED ON ITS ULTRASTRUCTURE IN THE LIVER OF EXPERIMENTALLY INFECTED ATHYMIC MICE

A new genus, Vittaforma n. g. is proposed for the human microsporidium Nosema corneum Shadduck, Meccoli, Davis and Font, 1990, based on the ultrastructure of developmental stages in the liver of experimentally infected athymic mice. The diplokaryotic arrangement of the nuclei is the only character that conforms with the description of the genus Nos ema. Sporogony is polysporoblastic, sporonts are ribbon-shaped, constr icting to give rise to linear arrays of sporoblasts and each parasite is enveloped by a complete cisterna of host endoplasmic reticulum. Com parison of N. corneum, with established genera revealed that there wer e none with the same combination of characters. Consequently it is pro posed that Nosema corneum be placed in a new genus as Vittaforma corne ae n. comb.