New Recording of Toxoplasma gondii in Wild Tortoise Testudo graeca Using Nested PCR Method

Toxoplasmosis is one of the most widespread zoonotic diseases, especially in warm and humid areas, and affects all mammals, including humans and many herbivores and carnivores. The present study investigated the Toxoplasma gondii (T. gondii) parasite in tortoises for the first time in Iraq using PCR technology. A total of 28 tortoises/Testudo graeca (T. graeca) were collected between October 2018 and March 2019 from the study stations and then sent to the Animal House, which belongs to the Department of Biology, Faculty of Education, University of AL-Qadisiyah, Iraq, to perform the dissection. The body cavity was opened, and all organs were removed. The tortoises' liver, heart, and brain were removed and kept at -20ºC until use. Afterward, the samples were subjected to DNA extraction. The Nested-PCR technique was implemented using two pairs of primers, and then the PCR products were analyzed using 1.5% agarose gel electrophoresis. The amplification of the gene during the first cycle indicated that 10 samples gave positive results with a total percentage of (11.9%), including five liver samples, three heart samples, and two brain samples (17.85%, 10.71%, and 7.14%, respectively). On the other hand, during the second cycle of the reaction, the amplification of the gene was obtained in seven samples (8.33%). The highest percentage of the presence of the gene was recorded in the tortoises' liver (14.28%) and the lowest in their brain (3.57%). This study is among the first to investigate the molecular detection of T. gondii in wild tortoises (T. graeca) in Iraq. The findings imply that tortoises have a role in transmitting T. gondii and are believed to acquire infection by feeding on small invertebrate animals or plants contaminated with the oocysts of the parasite.