DETECTION OF TOXOPLASMA-GONDII IN TISSUES OF SHEEP ORALLY CHALLENGED WITH DIFFERENT DOSES OF OOCYSTS

The presence of Toxoplasma gondii in blood, brain, cardiac muscle and skeletal muscle (gracillis and psoas) of sheep weeks after experimenta l infection with 10(5), 10(4) and 10(3) T. gondii oocysts was determin ed using the PCR technique. The study demonstrates that oral infection of sheep with T. gondii oocysts of the M3 isolate results in parasite s being detectable in tissues 6 weeks p.i. The PCR detection was much more sensitive than histological detection. Parasite DNA was detected more frequently and consistently in the group of sheep given 10(5) ooc ysts compared with those given 10(3) oocysts, The brain and heart were most frequently infected compared with the other tissues. (C) 1998 Au stralian Society for Parasitology. Published by Elsevier Science Ltd. All rights reserved.