Electron microscope studies of turkey sinus epithelial cells infected with Mycoplasma gallisepticum

Mycoplasma-infected turkey sinus epithelial cells were examined with an electron microscope. Mycoplasmas were found in large numbers during the first week of infection but were fewer in number by the sixth week. The infection was uncomplicated by secondary invaders during the first week but by the sixth week bacteria and fungal spores had appeared. Mycoplasmas were lying between cells and within cells, but relatively few were free in the exudate. Cellular degeneration was limited to the distal part of the cell. The nuclei and bases of the cells were not affected. Such cells would probably recover if the infection were removed. Cilia and microvilli were lost from heavily infected cells but not from adjacent uninfected cells.