Continuous Propagation of Plasmodium Gallinaceum in Chicken Erythrocytes

Abstract

Summary In vitro studies of the growth of P. gallinaceum in normal chicken plasma showed that an erythrocyte concentration equivalent to that of normal blood was most favorable to the parasite. Exposure of the plasma portion of a culture to 56°C. for an hour prior to mixing with the erythrocyte was found to increase parasite growth and multiplication. This effect was thought to be due to the heat lability of some inhibitory system present in normal chicken plasma. Continuous growth and multiplication of P. gallinaceum was obtained in erythrocytes suspended in a medium composed of heated plasma and erythrocyte lysate. During a series of ten successive subcultures the parasite density was maintained at a relatively constant level, while the dilution factor of the original culture rose to 1:19,440. The parasites of the final subculture reacted in young chicks and in A. aegypti mosquitoes in a normal manner.