SEROLOGIC AND PARASITOLOGICAL RESPONSES OF DOMESTIC CHICKENS AFTER ORAL INOCULATION WITH TOXOPLASMA-GONDII OOCYSTS

Four-week-old chickens were inoculated orally with 1,000 or 100,000 oo cysts of the ME-49 or GT-1 strain of Toxoplasma gondii, and their anti body responses were measured, using the direct modified agglutination test, latex agglutination test, indirect hemagglutination test, ELISA, and the Sabin-Feldman dye test. Antibodies against T gondii were dete cted by use of the modified agglutination test and ELISA within 2 week s of oocyst inoculation, and antibodies persisted until termination of the study by postinoculation day 68. The latex agglutination test was insensitive in detecting T gondii antibodies, and antibodies were not detected by use of the dye and indirect hemagglutination tests. Of ti ssues bioassayed in mice for tissue cysts by pepsin digestion of indiv idual organs of chickens on postinoculation day 68, tissue cysts were found in the brain of all 5, heart of 3, and leg muscles of 2, but not in the liver and breast muscles. None of the birds developed clinical toxoplasmosis.