In vitro development and antigen analysis of Sarcocystis

During the past year considerable progress has been made in developing an in vitro system for growing large numbers of merozoites (the disease-causing stages) of Sarcocystis species that infect livestock. This system provides researchers with a means to study mechanisms of immunity and pathogenesis; and may eventually be used to develop effective diagnostic tests and vaccines against these economically important parasites. In this article, Carl Speer and Don Burgess discuss their in vitro system and show how preliminary antigen analysis has helped to deduce a possible mechanism for the vascular damage commonly observed in Sarcocystis infections.