जर्नल ऑफ माइक्रोबियल पैथोजेनेसिस

Background: Toxoplasmosis is one of the most common parasitic infections caused by a protozoan named Toxoplasma gondii. Humans and carnivores can become infected by eating tissue cysts in row or semi-cooked meat or oocysts from cat feces. The aim of this study was investigation of different genotypes of Toxoplasma gondii isolates from cat feces, lamb and human pathological samples to determine the dominant types in Urmia city by amplifying GRA6 gen using PCR method. Materials and Methods: Meat samples were collected from butchery shops of Urmia city by cutting a small piece of diaphragm muscle. DNA extraction and PCR was done on these samples after being chopped. Stool samples from stray cats were collected from ruins and parks, and oocysts were concentrated by ethyl acetate formalin and were stained with acid fast technique. Microscopically positive samples were analyzed with PCR. The lymph node specimens were collected by reviewing the pathological records of Dr. Nemati Laboratory in Urmia city. The specimens that were suspected of toxoplasmosis, were also examined after hematoxylin eosin staining and microscopic confirmation, by PCR. Finally, 20 positive PCR products, including 5 stools, 5 lamb, 5 beef and 5 human lymph node samples were sent for sequencing. Results: Of the 20 cat feces samples suspected of having Toxoplasma oocysts, 7 samples were confirmed by PCR and from the 100 selected Lymph Node specimens, 5 samples were confirmed microscopically and PCR .sixty percent of 60 meat samples were also infected. Also, thirty percent of 60 beef samples were positive with PCR. Finally, out of 100 samples of Goat milk, 8 samples were positive and we were able to determine with PCR. Analysis of DNA sequencing revealed that all 5 lymph node specimens were from ME49 (genotype II) strain. lamb specimens were shown to be from ME49 (2 samples), GT1 or genotype I (2 samples), and VEG or genotype III (one sample) genotypes and four of five oocysts from stools samples were ME49, VEG or genotype III (one sample) strain and all beef samples were related to ME49 (genotype II) strain.Also, 2 samples of goat milk are related to GT1 or genotype I strain and 3 other cases are related to ME49 (genotype II) strain. So most of our samples were of ME49 strain. Conclusion: Genotyping is important because it can be used to identify the dominant genotype in the region and subsequently to take specific control measures as well as therapeutic measures against the risk of involved genotype. Most of the genotypes we obtained during this study, were of type II and this genotype appears to be predominant genotype in Urmia and regarding extremely high infection rate of meat samples, it seems that humans are mostly infected with Toxoplasma gondii by eating raw or undercooked meat.