Nosema muris n. sp., a New Microsporidian Parasite of the White Mouse (Mus musculus L.)

SYNOPSIS. A microsporidian, Nosema muris n. sp., is described from laboratory white mice in Czechoslovakia. I t differs from Nosema cuniculi (Levaditi, Nicolau and Schoen, 1923) and other Microsporidia in mice in that it develops in the omentum and heart muscle, iorming large masses of schizonts and spores. The parasite is distributed to other tissues (liver, spleen, fat, peritoneal muscles, connective tissue and brain) by infected mononudear cells, and then forms localized cysts in them. Kidney, lungs, adrenal glands, pancreas and salivary glands are not infected. The parasite can be transmitted via the placenta, by feeding on infected tissues, or by experimental injection of ascitic fluid.