Molecular analysis of Echinococcus granulosus: A comparison between cattle and sheep isolates in Babylon province, Iraq

Cystic echinococcosis (CE) is the metacestode parasite Echinococcus granulosus, a serious health and economic issue in many regions of the world. The study aimed to determine the genotypes and phylogenetic relationships of E. granulosus isolated from cattle and sheep using PCR-based genotyping of the mitochondrial cytochrome C oxidase subunit 1 (COX1) gene. Additionally, it identified the genetic diversity of E. granulosus circulating in various regions of Babylon province, Iraq. 112 liver hydatid cyst samples were collected from (52) slaughtered cattle and (60) sheep. The phenol-chloroform technique was used to extract hydatid cyst DNA, which was amplified by PCR using Cox1 gene-specific primers. Sequence analysis was conducted on 20 positive samples from both hosts using Multiple Sequence Alignment with ClustalW compared to Gen-Bank sequences. The UPGMA method was utilized in MEGA 11 to create a phylogenetic tree and evaluate its reliability. Out of the 20 sequenced samples, the sequencing results indicated that 15 samples belonged to the predominant G1 strain, two to the G2 strain, and three to the G3 strain, which were detected in both cattle and sheep. The predominant strain of hydatid cysts is the G1 strain in both cattle and sheep, which shows the important role of this genotype in the spread of the parasite in this region. The first detection of genotype G2 in cattle and sheep indicates genetic diversity and the spread of infection in different hosts. Subsequently, the results can be applied to lessen human infections and interfere with the parasite's life cycle.