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

Abstract

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. Organisms multiplied not only inside specific vacuoles originating from phagolysosomes but also in the cytoplasm itself. Lysis of the limiting membrane of some phagolysosomes, a normal function of endodermal cells, as well as rupture of vacuoles, provided the release of C. burnetii into the cytoplasm. The C. burnetii strain of greater virulence infected 100% of the endodermal cells, whereas the strain of lesser virulence infected only 60%. Budding of very small particles from the C. burnetii bodies was demonstrated. The particles were regarded as filterable forms of the organism. Despite the enormous multiplication of C. burnetii in the endodermal cells, organisms were only rarely detected in the vitelline blood vessels and liver sinusoids of the embryos. Peculiarities of the infectious process of C. burnetii in chicken embryos and possible mechanisms of limitation of spread of the infection are discussed.

Protein synthesis by intact Coxiella burnetii cells

“…Definition of these nutrients may be important in the development of a defined medium capable of sustaining axenic growth. Alternatively, the preincubation step used for mechanically released cells may have allowed the bacteria to differentiate to a sporelike quiescent state (9,13), thus rendering them more responsive to appropriate growth conditions. However, differentiating bacterial systems often demonstrate temporal changes in the patterns of proteins synthesized (11,19), and such differences were not readily apparent between these two cell types.…”

Q fever and Coxiella burnetii: a model for host-parasite interactions.

“…In other studies of infected chicken embryos (121), C. burnetii was found in all organs of the embryo including the liver, heart, and muscles by 11 days postinfection (p.i.). In more detailed experiments, the infection patterns in chicken embryos of the virulent Tabanidae-Kazakhstan and mildly virulent Apodemus microtii-Lauga strains of C. burnetii were compared (106). Both strains infected the yolk sac endodermal epithelial cells, and at 13 days p.i.…”

Histologic, immunofluorescence, and electron microscopic study of infectious process in mouse lung after intranasal challenge with Coxiella burnetii

“…Although it was serologically confirmed to be in phase 1, it rarely killed guinea pigs infected intraperitoneally. It multiplies extensively in cells of mouse spleen (4), chicken embryo yolk sac (24), guinea pig testicles (22), and MK2 cells of monkey kidney epithelium (23).…”