Host-parasite interaction and development of infraforms in chicken embryos infected with Coxiella burnetii via the yolk sac.

Two phase I strains of Coxiella burnetii of different virulence were injected into the yolk sacs of chicken embryos, and the yolk sacs and livers were examined at intervals by light, fluorescent, and electron microscopy. The high absorptive and digestive capacities of the yolk endoderm contributed to he entrance of the organisms into endodermal epithelial cells where C. burnetii multiplied.

[Combined use of serological tests for the purpose of the diagnosis and study of Q-rickettsiosis].

The combined use of the complement fixation test, the indirect immunofluorescent test and the ring precipitation test with C. burnetii antigen greatly enhances the effectiveness or serological study, as it allows not only to find out the spread of infection among population more completely, but also to differentiate, to a certain extent, "fresh" infectious process from immunological trace reaction. The arguments are presented in favor of introducing the antigen of C.

[The band precipitation test with the soluble Coxiella burnetii antigen in the diagnosis of Q rickettsiosis].

Soluble antigen obtained by the treatment of Coxiella burneti of the I phase with trichloracetic acid could be used in the capacity of a precipitinogen in the band-precipitation reaction in the diagnosis of Q-rickettsiosis and in mass epidemiological studies.