[Detection of chlamydia by the immunofluorescence method].

The possibility of detecting chlamydia by the direct immunofluorescence method was tested in the impression preparation of experimentally infected mice, chick embryos and naturally infected domestic mammals. In comparison with slight-microscope detection, this method was found to be sensitive and expedient. The greatest amount of antigen could be detected in the lungs of mice after intranasal infection already within 6 to 12 hours. In the other organs the findings were less ample; the visualization of the antigen had a good fluorescence brilliance if log 10 KEID50 was more than 3.0. In the tissues of chick embryos, the antigen could be detected in the impression preparations of the allanto-amnionic fluid, embryonal muscle, yolk sac, and chorio-allantoid membrane the fifth day after infection. After the intratracheal infection of ducklings with 1 000 000 infection doses, only individual specifically radiating cells with a low brilliance of fluorescence were detected in the organ preparations of ducklings killed 22 t0 57 days after infection. The method proved to be suitable for the detection of chlamydia in the organs of naturally infected domestic mammals in which a great amount of specifically fluorescing high-brilliance cells were found.