Pathogenesis of mycoplasmal pneumonia in swine
Livingston, C.W.; Stair, E.L.; Underdahl, N.R.; Mebus, C.A.
American Journal of Veterinary Research 33(11): 2249-2258
1972
ISSN/ISBN: 0002-9645 PMID: 4562966 Document Number: 48809
Twenty-nine hysterectomy-derived piglets, deprived of colostrum, were experimentally inoculated with the Nebraska isolate of Mycoplasma hyopneumoniae at one week of age. Two piglets were used as controls. Microscopic lesions were detected in one pig at six days after inoculation and were found in all inoculated pigs examined after the 10th day. Gross lesions appeared in pigs on the 14th day and, with one exception, in all pigs up to the 42nd day. Mycoplasma was reisolated from the lungs of inoculated pigs on the 10th day and, with one exception, until the 42nd day. Immunofluorescence was less sensitive, but could be demonstrated in the bronchial epithelium of most pigs from the 14th to the 42nd day. Electron microscopy revealed mycoplasmas adjacent to cilia and plasma membrane of epithelial cells lining the bronchioles and bronchi. Mycoplasmas were confined to surface structures and were not within epithelial cells.