Frequency and Sequence Analysis of Echinococcus granulosus Sensu Lato Isolated From Buffaloes in Northern Iran

Background Echinococcus granulosus sensu lato is one of the most important zoonotic parasites in many regions of the world. Cystic echinococcosis (CE) is a major economic and public health challenge in Iran. Objective This study aimed to determine the prevalence and genotypes of Echinococcus granulosus isolates from slaughtered buffaloes in Guilan Province, northern Iran. Methods We examined 384 buffaloes at the Talesh county abattoir, isolating 42 hydatid cysts. We sequenced the mitochondrial cytochrome c oxidase subunit 1 (CO1) and NADH dehydrogenase subunit 1 (ND1) genes for genotype analysis. Molecular phylogeny and haplotype network analysis was performed for the isolates. Results Our results showed that 10.9% of the buffaloes were infected with hydatid cysts, with 90.5% of infections in the liver and 9.5% in the lungs. Only one liver cyst was fertile; the rest were non-fertile. Amongst the infected animals, 21.4% (9/42) were male, and 78.6% (33/42) were female. No significant gender-related difference in infection rates was observed (p = 0.057); however, a significant relationship was found between age groups and infection (p = 0.030). Sequence analysis identified all isolates as belonging to the G1 genotype of E. granulosus, with five haplotypes being identified. Conclusion The study highlights the high prevalence of hydatid cysts in buffaloes, though fertility was low, suggesting a minor role for buffaloes in CE epidemiology in this region. Similar to other studies, our research shows that infection rates increase significantly with age.