Cultivation of Trypanosoma cruzi in the Developing Chick Embryo

Abstract

ALTHOUGH Trypanosoma cruzi, the causative agent of Chagas' disease in South America, has been successfully cultivated in the embryonic tissues of the chick, attempts at growing this parasite in the developing chick embryo have hitherto led to inconclusive results. Roubaud and Romana¹ inoculated T. cruzi into the chorio-allantoic membrane of chick embryos from (a) a rich culture ; (b) drops of liquid excreta of Rhodinus prolixus containing metacyclic forms ; and (c) citrated blood of an infected guinea pig containing numerous large and active trypanosomes. The results were negative, and no infection was observed, except that in one embryo inoculated with the citrated blood a single trypanosome was found to have persisted on the membrane a week after inoculation. Rodhain and van den Berghe² inoculated a dozen eggs with a strain of T. cruzi cultured in Novy–MacNeal–Nicolle medium. Three of the embryos became 'infected'; but attempts to effect a second passage in embryos did not succeed, and sections of the membrane of an 'infected' embryo did not show any trace of an invasion of the membrane or intracellular developmental stages. Rodhain and van den Berghe concluded that a true infection had not been established and that, probably, cellular invasion of the chick embryo does not occur, but that, as the parasite grows readily in tissue cultures of the chick embryo, the results need verification.