Cystic Echinococcosis in Central Iran: G1 and G6 Genotypes in Patients

Cystic echinococcosis (CE) is caused by Echinococcus granulosus sensu lato. In Central Iran, no molecular information is available on CE in humans. Therefore, in this study, we identified the genotyping of hydatid cysts obtained from patients with CE in central Iran using mitochondrial cytochrome c oxidase subunit I (cox1) gene. Hydatid cysts were obtained from 19 patients referred to Shahid Sadoughi, Mojibian, and Mortaz Hospitals, Yazd, Iran from 2018 to 2020. Informed consent was obtained from all included patients. After DNA extraction, amplification was done using cox1 gene. Phylogenetic analysis was performed using MEGA7. Of the 19 patients, 11 (57.9%) were male and eight (42.1%) were female. The mean age of the patients was 35.645 ± 2.55 years old. Regarding cyst location, of eight isolates from lung, six and two belonged to G1 and G6, respectively; and all liver cysts were G1 genotype. The spleen and neck cysts had G1 and G6 genotypes, respectively (p > 0.05). All cysts with a diameter in the range of 5-10 cm (n = 9) and large cysts (>10 cm; n = 5) were identified as G1 (p = 0.002). The maximum likelihood tree topology demonstrated the maximum similarity of G1 among Iran and worldwide (99%-100% likelihood). Based on our results, it seems that the sheep-dog cycle in the infection of humans by Echinococcus granulosus in this study area has the most important role compared with the other cycles such as the camel-dog one.