Abstract
Background:
Hydatid disease remains a major concern in sheep farming, particularly in endemic areas such as Iraq.

Aim:
This study aimed to explore the molecular characteristics of Echinococcus granulosus isolated from sheep using multilocus genetic analysis.

Methods:
Fertile cysts were collected from sheep slaughtered in Diwaniyah and processed for DNA extraction. Four genetic loci—ACT-2, COX1, CYT, and ND1—were amplified by polymerase chain reaction (PCR) and sequenced to evaluate the diversity of the parasite.

Results:
Each gene yielded fragments of expected lengths, and no contamination was observed in the negative controls. Sequences from sheep isolates were submitted to GenBank, with accession numbers PV959524–PV959533 (ACT-2), PV959270–PV959279 (COX1), PV975191–PV975200 (CYT), and PV975171–PV975180 (ND1). BLAST comparisons revealed identities ranging from 95.6% to 100%, with close matches to isolates from China, Brazil, Estonia, and Turkey. Phylogenetic trees showed clear clustering of local sheep strains with global references, particularly within the G1 lineage. Multiple sequence alignments confirmed a high degree of similarity with minor genetic variation.

Conclusion:
These results demonstrate the genetic stability of E. granulosus in sheep in southern Iraq and support its inclusion in regional parasite mapping efforts. The data also emphasize the importance of sheep as intermediate hosts contributing to the persistence and spread of this zoonotic parasite. The genetic analysis of Echinococcus granulosus from sheep showed close relationships with international strains, reflecting regional transmission and limited sequence divergence. Molecular typing remains essential for the epidemiological control and future vaccine development.

Key words: Alignment; Diagnostic; Liver; Sequencing; Zoonosis.