Genetic characterization of Echinococcus granulosus in camels, cattle and sheep from the south-east of Iran indicates the presence of the G3 genotype

Echinococcus granulosus, the aetiologic agent of cystic echinococcosis (CE), is one of the most important zoonotic helminthes worldwide. Isolates of the parasite show considerable genetic variation in different intermediate hosts. Several genotypes and species are described in different eco-epidemiological settings. This study investigated E. granulosus genotypes existing in livestock and humans from the province of Kerman, located in south-eastern Iran, using sequencing data of cox1 and nad1 mitochondrial genes. Fifty-eight E. granulosus isolates, including 35 from sheep, 11 from cattle, 9 from camels and 3 from goats, were collected from slaughterhouses throughout Kerman. One human isolate was obtained from a surgical case of CE. Mitochondrial cox1 and nad1 regions were amplified using polymerase chain reaction (PCR) and 38 isolates were sequenced. Genotypes G1 (73.7%), G3 (13.2%) and G6 (13.1%) were identified from the isolates. G1 was the most common genotype from sheep (86.7%), cattle (80%), camels (44.4%) and goats (100%). Sheep, cattle and camels were also found to be infected with the G3 genotype (buffalo strain). The human isolate was identified as the G6 genotype. Results showed that the G3 genotype occurred in different animal hosts in addition to G1 and G6 genotypes.