[Experimental infection of guinea pigs with Clamydia. 2. Fluorescent antibody examinations]

The direct fluorescent antibody technique was applied to blood smears and organ impression smears from guinea-pigs killed at various times during 13 weeks following nasal infection with a bovine strain of Chlamydia. Antigen inclusions were demonstrated one hour after infection in blood granulocytes, after 3 hours in most of the organs examined and after 6-12 hours in all the organs. Antigen was present throughout the period of observation in blood smears and samples from nasal mucosa, trachea, lung, small intestine, spleen and liver. It seemed that polymorphonuclear granulocytes played an important part in the pathogenesis of generalized chlamydial infection. In the case of intranasal inoculation, the nasal mucosa was evidently the site of the initial infection and proliferation of the agent, and the origin of primary chlamydaemia. For the initiation and maintenance of the secondary period of blood infection, the lungs and trachea were the principal site of multiplication of the agent; spleen, intestinal mucosa and CNS were also involved to a lesser extent. The antigen content of lung, trachea, nasal mucosa and spleen at each stage of infection was generally correlated with the extent and intensity of the inflammatory reaction.