Molecular identification and genetic diversity of Echinococcus granulosus sensu stricto in livestock from Qinghai lake on the Qinghai-Tibetan plateau.

Echinococcus granulosus sensu stricto (G1 genotype), the predominant causative agent of zoonotic cystic echinococcosis, continues to jeopardize public health across the pastoral ecosystems of the Qinghai-Tibetan Plateau. Here, we provide a novel molecular genetic evidence from the Qinghai Lake by investigating hydatid cysts in two key livestock species sheep and yaks. Through an innovative dual-marker strategy targeting mitochondrial Cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes, we conducted PCR amplification and haplotype analysis, combined with maximum likelihood (ML)-based phylogenetic reconstruction and divergence time estimation. The results demonstrated that all 13 positive samples belonged to the Echinococcus granulosus genotype 1 of E. granulosus s. s. and reveal a pivotal Miocene-Pliocene divergence event (5.8 ± 0.5 million years ago) within Echinococcus spp., establishing critical evolutionary benchmarks. This study not only provides updated epidemiological data on echinococcosis in the Qinghai Lake, but more importantly, deliver critical molecular evidence for precision control of zoonotic diseases in high-altitude pastoral ecosystems.