A model of the deciliation process caused by Mycoplasma fermentans strain incognitus on respiratory epithelium.

The aim of this study was to investigate by light microscopy as well as by scanning and transmission electron microscopy the deciliation process which takes place on the respiratory epithelium of tracheal explants after experimental infection with Mycoplasma fermentans strain incognitus. Time-point photography allowed distinguishing five phases which occurred during the infection on the epithelial cell surface: (1) Attachment of M. fermentans to the cilia causing clumping of the cilia tips; (2) matting of cilia into bundles; (3) formation of abnormally shaped and shorter cilia; (4) collapse of cilia onto the epithelial cell surface; and (5) widespread loss of cilia. Based on the photographic images, a schematic model of the deciliation process was developed. Various potential factors contributing to the cilia destruction are discussed, including the release of mycoplasmal toxins, the physical presence of a high number of M. fermentans cells attached to the cilia, and the depletion of culture medium components by the mycoplasmas. This model of M. fermentans strain incognitus infection of respiratory epithelium is important for understanding mycoplasmal pathogenicity on a comparative level.