[Interaction of Rickettsia akari with the host cell in vitro: multiplication, formation of spheroplast-like forms and its destruction in phagolyosomes].

The electron microscopic study of the interaction of R. akari, strain CK, with the monolayer culture of L-cells was made 4 days after inoculation. Rickettsiae multiplied by transverse binary fission immediately in the cytoplasm of the cells and left the cells by gemmation, surrounded with plasmolemma and a fragment of the host cytoplasm. Alongside with multiplying rickettsiae, spheroplast-like rickettsiae and rickettsiae at the stage of destruction were regularly observed in phagolysosomes. The authors suggest that the normal interaction of rickettsiae with the host cell may be realized by three following routes (1) reproduction, (2) destruction in phagolysosomes and (3) formation of altered (anomalous) forms. The ability of the vegetative forms of rickettsiae and chlamydiae to yield spheroplast-like forms (the initial phase of bacterial L-transformation) indicates that these organisms are similar to bacteria and cannot be themselves regarded as L-forms.