Phylogenetic analysis and genetic evaluation of the Echinococcus granulosus antigen B subunit 2 gene isolated from sheep in Al-Diwaniyah, Iraq.

Background: Hydatid cysts are an immature form of Echinococcus granulosus tapeworm, which causes zoonotic illness, echinococcosis (sometimes called hydatidosis). There are 10 officially recognized genotypes (G1-G10) of this parasite.

Aim: The current study aimed to sequence and characterize the genotypes of E. granulosus using the antigen B subunit 2 gene isolated from sheep in Al-Diwaniyah City, Iraq.

Methods: Using specific antigen B subunit 2, 50 hydatid cysts were collected from the livers of sheep at a local slaughterhouse between March and October 2023. DNA was obtained from the hydatid fluid of sheep cysts. Protoscolices from fertile cyst fluid were also obtained. Conventional polymerase chain reaction (PCR) targeting the antigen B gene was performed on the extracted DNA of samples. PCR was performed followed by sequencing and phylogenetic analysis of PCR 7 positive isolates.

Results: The predominant genotype in the sheep population was the G1 strain. Furthermore, the sequenced isolates exhibited a high degree of correlation with local and regional Iran E. granulosus sequences, demonstrating genetic diversity compared with reference strains. The current isolates were assigned accession numbers by the NCBI as follows: OR232318.1, OR232319.1, OR232320.1, OR232321.1, OR232322.1, OR232323.1, and OR232324.1.

Conclusion: The findings indicate that E. granulosus has diverse genotypes and is mostly linked genetically to isolates from neighboring countries, such as Brazil and Iraq.