investigation on toxoplasma gondii infection in domestic animals in urmia by pcr and rflp

infection by the protozoan parasite toxoplasma gondii, is widespread in humans and many other species of warm-blooded animals. it can cause significant morbidity and mortality in the developing fetus and in immunocompromised individuals, including humans with acquired immunodeficiency syndrome - aids or submitted to cancer chemotherapy. among livestock, sheep and goat are more widely infected with t. gondii. this parasite is a major cause of abortion, with significant economic losses to sheep and goat breeders. we applied the polymerase chain reaction for detection of the pathogenic protozoan t. gondii based on its b1 gene. the b1 gene is present and conserved in all six t. gondii strains identified to date. for this purpose blood samples were collected from a total of 372 animals (144 dog, 7 cat, 126 horse, 50 cattle and 45 sheep) from urmia region. in this study, pcr was performed using the previously described primers (fuentes et al., 1996)(10), which were designed to detect the b1 gene of t. gondii. the targeted b1 gene is highly conserved in all t. gondii strains and is multiple copy genes within the t. gondii genome. the method used for the characterization of t. gondii strains implied digestion with saci restriction enzyme of the fragments amplified. the results indicated 3 positive samples (2 horse and 1 sheep samples). the 194 bp fragment was generated in all positive samples tested and one rflp patterns were obtained. the results indicated that the same strain of t. gondii has been infected sheep and horse in the study region.