Studies on the excystation of different species of Eimeria in vitro.

Abstract

The role of enzymes in the excystation of an embryo-adapted strain ofE. tenella (TA) was investigated; 0.1% crude trypsin or pure trypsin in combination with 0.5% bile salt resulted in 75% and 58% excystation respectively. Both enzymes were more effective than chymotrypsin. Addition of 0.01% chymotrypsin to 0.1% purified trypsin resulted in 76% excystation suggesting that both trypsin and chymotrypsin may be important for excystation in vitro. Pre-incubation of sporocysts in 2% bile salt prior to the addition of enzyme resulted in lower excystation. Sporozoites released at various enzyme concentrations did not differ in infectivity when inoculated into chicken embryos.