The occurrence of Mycoplasma arthritidis in the throat and middle ear of rats with chronic respiratory disease.

Twenty-three rats with chronic respiratory disease were examined for the presence of Mycoplasma arthritidis in the throat and middle ear. Samples were taken at necropsy and swabbed onto an agar medium. Morphologically typical colonies were subcultured and identified serologically. All of the rats showed evidence histopathologically of chronic respiratory disease, and typical M pulmonis colonies were isolated from 21 of 23. M arthritidis was isolated from 7 (30=) of the middle ears and 3 (13%) of the throats, confirming a previous observation of the occurrence of this organism in the middle ear of rats and also indicating it can be present in the throat.