Depression of bursal follicle formation by Candida albicans infections.

Sub-lethal i.v. inoculations of Candida albicans into 12-day-old chick embryos have been shown to cause a depression of follicle formation in the bursa of Fabricius. This depression occurred in the absence of any infection in the bursa, although candidal encephalitis was a frequent manifestation of the disseminated infection. A similar depression of bursal follicle formation was caused by the administration of viable C. albicans on to the embryonic chorio-allantoic membrane, in the absence of any disseminated infection. Non-viable extracts of disrupted C. albicans administered on to the chorioallantoic membrane also caused a depression of bursal follicle formation. This immunodeficiency produced by an endotoxin-like principle at a susceptible stage in the development of the chick has been considered in terms of human immunological development and the neonatal occurrence of C. albicans.