Enhancing hydatid cysts diagnosis utilizing cell-free DNA as a sensitive biomarker for Echinococcus spp

Echinococcosis is an important zoonosis that leads to significant health problems and economic losses in livestock. The study aimed to detect cell-free DNA (cfDNA) from hydatid cysts in blood-derived samples and to determine the species/strains of Echinococcus. Hydatid cysts were initially collected from slaughtered sheep and tested for their viability using an eosin stain. Twenty-five rats were injected with 3000 protoscolices into the peritoneal cavity, and after a two-month observation period, they were autopsied. The Casoni test was performed to assess the hypersensitivity reaction to hydatid antigens. Polymerase chain reaction (PCR) was employed to identify Echinococcus spp. from multiple samples, including the cysts, sera, and plasma. The NADH dehydrogenase genes (nd1) of E. granulosus were targeted at 657 bp, and partial mitochondrial DNA sequences were obtained. The majority of the cysts (80%) were considered actively fertilized/viable. According to the molecular test, all studied samples were related to E. granulosus. The study concluded that E. granulosus is a common species in sheep populations in Basrah. Using cfDNA in plasma is a more efficient method for detecting hydatids than serum and faecal samples. This method is considered highly accurate and feasible for evaluating hydatid cysts in the intermediate hosts, which is critical for the control and therapy of parasitic infections.