A Molecular and Serological Study of Toxoplasma gondii Infection in Slaughtered Sheep in Mashhad Area

BACEKGROUND: 

Toxoplasmosisis one of the most important zoonotic diseases in Iran and the world. OBJCTIVES: Due to the high consumption of lamb meat and the high frequency of Toxoplasma infection in sheep in Iran, the aim of study was to determine frequency of Toxoplasma infection in the slaughtered sheep of Mashhad area.

In order to do this study, from summer 2015 to spring 2016, 25 blood and 25 heart muscle samples were seasonally collected from Torghabae slaughterhouse in Mashhad area. The samples were transferred to parasitology laboratory. First, the blood samples were centrifuged and the serum samples were isolated, then a portion of the heart muscles sample was taken for PCR examination. The sera and muscles samples were kept at -20 ºC in freezer until examination time. The sera samples were examined to detect antibody against T.gondii by ELISA method. DNA of heart muscle was extracted by commercial extraction kit and was examined to detect Toxoplasma DNA by nested –PCR.

In the present study, of 100 sampled sheep, only 1 (1%) of the serum samples was seropositive, while 22 (22%) of the DNA samples were PCR positive. In this study, the highest frequency of Toxoplsma PCR-Positive was seen in spring and the lowest in summer in sheep. Also, the result of this study showed that the agreement between the molecular and EISA method was “fair”.

Based on the high frequency of Toxoplasma infection in heart muscle of sheep, it seems that the risk of transmission of Toxoplasma infection from sheep meat is high.