[Multiplication of coxiella burneti in different tissues and organs of embryonated eggs (author's transl)]

Multiplication and content of Coxiella burneti after infection of the yolk sac were studied in different tissues and organs of embryonated hen's eggs (yolk sac, CAM, allantoamnion, amniotic fluid, liver, muscles, spleen, and heart). Demonstration of the agent was performed from the 6th to the 11th day p.i. by direct microscopic methods (Stamp and auramine staining, fluorescent antibody technique); the Coxiella content was determined by titration in embryonated hen's eggs. Coxiellae could be demonstrated, apart from the yolk sac membrane, also in the intestine and CAM from the 7th day p.i., and in the other organs examined from the 11th day p.i. by means of microscopy. For the same period, embryonic death rates (ELD50) and egg infectivity (EID50) were determined separately. The highest numbers of Coxiella were consistently found in the yolk sac membrane (ELD50 10(4.0)-10(5.2); EID50 10(6.0)-10(7.8)). In the intestine, CAM, allantoamnion, and amniotic fluid, ELD50 values were between 10(2.0) and 10(2.8), EDI50 values between 10(4.8) and 10(5.2), on the 11th day p.i.. Titres were lower for muscles, liver, spleen, and heart of infected embryos.