Jp. Dubey et al., Characterization of an unidentified Sarcocystis falcatula-like parasite from the South American opossum, Didelphis albiventris from Brazil, J EUKAR MIC, 47(6), 2000, pp. 538-544
An unidentified isolate of a Sarcocystis falcatula-like parasite was obtain
ed from the lungs of budgerigars (Melopsittacus undulatus) fed sporocysts f
rom a naturally-infected South American opossum, Didelphis albiventris from
Brazil. Four captive budgerigars fed sporocysts from the opossum intestine
died of acute sarcocystosis 8, 10, and 12 days after oral inoculation (DAI
); one budgerigar was killed 12 DAI when it was lethargic. Schizonts and me
rozoites found in the lungs of the budgerigars reacted mildly with polyclon
al S. falcatula antibody. The parasite was isolated in equine kidney cell c
ultures inoculated with lung tissue from a budgerigar that was killed 12 DA
I. Two budgerigars inoculated subcutaneously with 100,000 culture-derived S
. falcatula merozoites developed acute sarcocystosis and S. falcatula-like
schizonts were found in their lungs 15 and 16 DAI. Four budgerigars kept as
unfed controls in the same environment remained free of Sarcocystis infect
ion. The parasite underwent schizogony in African green monkey kidney cells
and bovine turbinate cells. Merozoites divided by endopolygeny, often leav
ing a residual body. Polymerase chain reaction studies using primers JNB33/
JNB54 and Hinf I and Dra I digestion indicated that the isolate was not S.
falcatula. Results of this study indicated that the South American opossum,
D. albiventris, is a definitive host for yet another S. falcatula-like par
asite.