ULTRASTRUCTURAL-STUDY ON THE INTERACTION OF MYCOPLASMA-GALLISEPTICUM WITH THE CHICKEN TRACHEAL EPITHELIUM

  • 1 January 1979
    • journal article
    • research article
    • Vol. 40  (7) , 1009-1014
Abstract
Seven day old chickens were intratracheally inoculated with M. gallisepticum. The tracheas collected 6 and 14 days after chickens were inoculated were subjected to titration of Mycoplasma and examination by EM and light microscopy. The Mycoplasma organisms grew well; 107-108 color-changing units in 1 mg of tissue were determined. Tracheal lesions occurred in close association with the presence of mycoplasmas and were characterized by degeneration of the epithelial cells and inflammatory cellular infiltration of the mucosa. Mycoplasmas were predominantly found extracellularly and only rarely in phagocytic vacuoles of the epithelial cells. Although the mycoplasmas exhibited considerable pleomorphism in size and shape, most of them were oval or round and the largest diameters were between 300 and 700 nm. Elongated and irregular forms were observed, particularly in those mycoplasmas adhering to the epithelial cells. The organism had a limiting unit membrane, the fibrillar nuclear area, the peripheral cytoplasmic area containing numerous ribosomes and a terminal bleb structure. Mycoplasmas attached to the epithelial cells by their blebs close to the host cell membrane. At the attachment site, neither fusion of the membranes of the mycoplasma and host cell nor injury to the host cell membrane could be demonstrated. The intimate association between the adhering mycoplasmas and the epithelial cells might be an important factor in pathogenesis of the disease.