[Electron microscopic determination of the localization of the group-specific antigen of Halprowise (Chlamydiae) by the direct immunoperoxidase method].

The direct immunoperoxidase technique was applied to the study of the localization of a group-specific antigen of Halprowiae (Chlamydiae) in the causative agents of meningopneumonia (strain MP) and of paratrachoma (strain LB-I) at the individual stages of their developmental cycle in the L-cell (16, 24 and 48 hours after infection of the culture). The product of reaction to peroxidase pointing to the localization of the group-specific antigen was localized not only on the surface, but in the whole thickness of the cell wall of the initial bodies in the form of an even electron dense layer, 200--280 A in thickness. A weak positive reaction was also noted on the outer layer of the sytoplasmic membrane. The periplasmic space remained free of the reaction product. Localization of the reaction product in the intermediate and elementary bodies remained unchanged. At the initial stages of the developmental cycle (16 hours after the infection) the reaction) the reaction product was revealed not in the whole cell wall, butin some of its areas only. There were found no qualitative differences in the localization of the group-specific antigen in the Malprowiae strains under study.