In vitro cultivation and experimental inoculation of Sarcocystis falcatula and Sarcocystis neurona merozoites into budgerigars (Melopsittacus undulatus).

This is a report of the isolation and in vitro propagation of merozoites of Sarcocystis falcatula. Culture-derived S. falcatula merozoites remained infectious after several passages in tissue culture as determined by the susceptibility of experimentally inoculated Melopsittacus undulatus that died of pulmonary sarcocystosis after experimental inoculation. There was no obvious clinical disease or lesion when Sarcocystis neurona merozoites were used to inoculate M. undulatus. On the basis of the biological infectivity data, S. falcatula and S. neurona are not synonymous as suggested from limited molecular data.