A High Sensitive Nested PCR for Toxoplasma gondii Detection in Animaland Food Samples

Toxoplasma gondii is a major food and waterborne transmitted parasite world-wide. The tissues and meatsamples of many warm blooded animals can contain tissues cysts from chronic toxoplasmosis. Water and vegetablecan be contaminated by the parasitic oocysts shed through the feces of infected cats, representing the definitivehost of the parasite.A sensitive PCR for Toxoplasma gondii detection is described. The first step amplified the region between the28S and 18S rDNA in the closely related T. gondii and Neospora caninum; RFLP analysis distinguished the DNAfrom the two morphologically identical parasites. Although N. caninum is not involved in human transmission, so far,it is important for animal health since is a major responsible for abortion in cattle.The nested PCR was used in a dilution assay in pork sausage samples spiked with T. gondii parasitic DNA. Theanalysis showed that up to 200fg equivalent to two single parasites only, could be detected. Similar detection limitfor T. gondii can be obtained with real-time PCRs, but real time methods need special consumables and expensiveequipment.