Echinococcus granulosus comparative genotyping in sheep in Saudi Arabia and Egypt

Background: Cystic echinococcosis, which is triggered by the parasite Echinococcus granulosus, is a global zoonotic disease that is common in rural regions in which there are frequent encounters between dogs and other domestic animals. The disease can have devastating consequences, impacting the health of people and animals and leading to huge financial losses, especially in the agricultural industry. In the Kingdom of Saudi Arabia (KSA) and Egypt, despite the high incidence of disease, few investigations have been conducted into the genetic variation in species of the genus Echinococcus.
Aim: This study sought to compare the genetic features of the hydatid cysts carried in sheep in KSA with those found in Egypt.
Methods: DNA from the protoscolices was used in a PCR targeting the mitochondrial NADH dehydrogenase 1 (NAD1), cytochrome c oxidase subunit 1 (COX1), and nuclear actin II (ACT II) genes, and the resulting amplification products of 30 KSA and Egyptian isolates were sequenced and compared.
Results: Among the sheep in KSA, the overall prevalence of cystic echinococcosis was 0.51%. Of the sheep cyst DNA samples, 95%, 100%, and 52% were positive for the Cox1, nad1, and act II genes, respectively. Targeting all three genes, all KSA samples belonged to the E. granulosus genotype (G1), whereas all Egyptian isolates belonged to E. granulosus (G1) and E. canadensis (G6).
Conclusions: We conclude that isolates of E. granulosus from the two countries shared a common origin in Arabic North Africa, with sheep and camels as common hosts.