Pathogenicity of Mycoplasma pulmonis in ependymal organ culture.

Ependymal organ culture was used as a model to study the effect of Mycoplasma pulmonis on the ciliated ependyma of the rat. Reduced ciliary activity or ciliostasis occurred 48 to 72 h after infection. Scanning electron microscopy showed that numerous organisms were associated with the cytoplasmic membrane of host cells beginning at 24 h, and transmission electron microscopy indicated that M. pulmonis cytadsorbs to the cell surface. Lesions observed in the organ cultures were limited to changes at the cell surface. These changes included reduction in microvilli density, matting of cilia into bundles, collapse of the cilia onto the cell surface, deciliation of the ependymal cells, and flattening of the cell surface. The results indicated that the response of the ependymal cell to M. pulmonis is similar to that which occurrs in Mycoplasma-infected tracheal and oviduct organ culture systems.