[Microscopic and ultramicroscopic lesions from experimental mycoplasma infection in respiratory tract of chickens. Possible difference between pathogenic and non pathogenic strains (author's transl)].

For three weeks after experimental infection of trachea and scroll bone with Mycoplasma gallisepticum no lesions were detected in scroll bone, but only an abundant mucous secretion. Mycoplasmas were present and adhered to cilia of epithelial cells. In trachea an almost complete destruction of cilia was observed allowing swollen epithelial cells to appear with mycoplasmas adhering to villi. Strain W31 serotype C caused no lesions but cells and cilia were covered with a thick layer of mucous.