[Unusual small forms in the growth cycle of halprowia (chlamydia) and their possible relation to manifestations of L-transformation].

The authors carried out a comparative electron-microscopic study of the ultrastructure and the developmental cycle of 15 Halprowiae (chlamydiae) strains isolated in different pathology from man and animals. Halprowiae were cultivated in the yolk sac epithelium of the developing chick embryos and in the L-cell monolayer cultures without any special action of the antibiotics and medicines. Formation of minute round structures ("minute forms"), 50--120 nm in diameter, separating from the protoplast into the periplasmic space and surrounded with cytoplasmic membrane by the vegetative forms of a number of strains (MP, AP-23, 25-SM, LB-1, MyB), is described. Along with minute forms, Halprowiae formed polymorphous giant bodies with long protrusions into the inclusion cavity; there was also a separation of vesicles of the cell wall membrane. This apparently indicated a structural derangement of the cell wall in these vegetative forms of Halprowiae. On the basis of similarity of the mentioned structures detected in Halprowiae reproduction to the known morphological characteristics of the L-form bacteria a possibility of L-transformation in Halprowiae during the normal developmental cycle as a peculiar compensatory adaptation to the action of host cell is supposed.