Abstract
Some studies on experimental infection with Mycoplasma pneumoniae (M. pneumoniae) have been reported. However, these models were unable to appear the transitional changes of epithelial cells in respiratory tract. In the present study, the tracheal rings of human embryo were used in organ culture for the purpose of continual observation on the host-parasite relationship in respiratory tract of man.
In this system, distinct cytopathology was found to appear not only by isolated strains but also by standard strain (Mac strain) which was not able to produce effective damage to epithelium in hamster tracheal organ culture system. This observation suggest that precise virulence of M. pneumoniae strain was detectable only by experimental infection used epithelial cells of human respiratory tract.
By the immunofluorescent technique, specific fluorescence was proved in the epithelial cytoplasma and covered fluorescent material was found on epithelial surface of infectious tracheal rings. In the electron microscopic findings, many infectious ciliated epithelial cells lost most of their cilia and some of remained cilias were metamorphosed.
Microvillies of cells appeared as short rounded projections. Numerous rounded bodies which had about 150mμ. Diameter were found on the luminal border of cells and in the intercellular spaces but these structures were not found in the intracellular. Relationship between M. pneumoniae and the epithelial cell which was demonstrated by the results of immunofluorescence and electron microscopy may have implications for further understanding of M. pneumoniae infections.
