Experimental infection with Mycoplasma pneumoniae in the young hamster: location of ferritin-labeled antibody binding to infective tissue.

pathological examinations of the respiratory tract of young hamsters infected with Mycoplasma pneumoniae by inhalation of aerosol were carried out for up to a maximum of 98 days after infection. Mycoplasma pneumoniae organisms were found mainly in the pharynx and larynx for the first two weeks, then they con tinued to proliferate in the main bronchi or intrapulmonary bronchi for up to 98 days. On the third day after infection, inflammatory changes consisting mostly of infiltration with lymphocytes and monocytes appeared in the bronchial epithe lium. These inflammatory changes proceeded to the peribronchial or interstitial tissues and reached a maximum on the 21st day after infection. After that, they showed a tendency to decrease and were replaced partially by atelectatic and emphysematous changes. These pathological processes seemed to be associated with the presence of Mycoplasma pneumoniae. On electron microscopic examina tion by the double staining and the ferritin-antibody method, Mycoplasma