Genotyping and Identification of Antigen B Gene Polymorphism of Echinococcus granulosus in Edirne, Thrace, and the First Report of Genotype G2 (Tasmanian Sheep Strain) in Turkey

BACKGROUND: Echinococcus granulosus is the causative agent of cystic echinococcosis in humans and livestock. It is common worldwide. Cystic echinococcosis is still an important public health problem in Turkey, which is an endemic region. AIMS: To genotype Echinococcus granulosus isolates and investigate antigen B gene polymorphism in Thrace, Turkey. STUDY DESIGN: A cross-sectional study. METHODS: Seventy-five hydatid cyst materials obtained between June 2020 and May 2021 were included in the study. Hydatid cyst materials were collected from 12 humans from various hospitals in Edirne and 63 from slaughterhouse animals during the same period. Cyst materials were localized in 8 livers and 4 lungs in humans, 23 livers and 17 lungs in cattle, and 13 livers and 10 lungs in sheep. In the first step, the 12S ribosomal RNA gene was amplified by polymerase chain reaction for all samples and run on an agarose gel. Band patterns were used for strain typing. Then, the selected samples that represented each of the band patterns obtained by single-strand conformation polymorphism analysis were sequenced for AgB1, AgB2, mt-CO1, and mt-ND1 genes. RESULTS: Three different genotypes in Edirne, Thrace, Turkey, were observed for Echinococcus granulosus: G1 (domestic sheep strain), G2 (Tasmanian sheep strain), and G3 (buffalo strain). G1 was the dominant genotype in Edirne, and G3 was the second most common. Additionally, polymorphism in AgB1 and AgB2 gene regions was found. CONCLUSION: This study is the first to report on Echinococcus granulosus G2 (Tasmania sheep strain) in Turkey and G3 (buffalo strain) and antigen B polymorphism in Thrace. The study results will contribute to the prevention and control programs for cystic echinococcosis in Turkey and worldwide.