Abstract
Echinococcosis caused by the larval form of Echinococcus granulosus (E. granulosus) is known as an important zoonotic disease in various parts of the world, including Iran. The genetic diversity of this parasite is very high, particularly in areas where the disease is endemic. It has been suggested in the literature from different parts of the world that diverse factors, such as parasite life cycle, transmission pathways, pathologic disease, immunization, and disease control can be affected by the genetic diversity of the parasite. Various studies indicated sheep strain G1 as the most common genotype throughout the world. This strain is commonly found in the liver and lung repeatedly causing echinococcosis in humans, sheep, and cattle. The present study was conducted to determine the genetic affinity between the protoscolex of E. granulosus in humans and sheep in East Azerbaijan province, Iran for the first time. A total of 120 hydatid cyst samples were collected, 60 of which were from people who referred to the hospitals of East Azerbaijan and 60 were from the sheep slaughtered in Tabriz slaughterhouse. Following DNA extraction, certain regions of the cox1 gene were amplified and evaluated by the polymerase chain reaction. The replicated parts in all isolates had the same size of 450 bp. Electrophoresis was followed by selecting a total of 60 suitable samples, including 30 human samples and 30 sheep samples and sending them for genome sequencing. The overlap of the samples was investigated using the BLAST software. The results of BLAST, sequencing, and overlap demonstrated a genetic linkage of approximately 91.76% between the protoscolex of E. granulosus in human and sheep.