Phylogeography, Genetic Diversity and Population Structure of Echinococcus granulosus Sensu Stricto Inferred by Mitochondrial DNA Markers between Southeast of Iran and Pakistan

Abstract

Background: Current study was designed to provide a better insight into the circulating genotypes, genetic diversity, and population structure of Echinococcus spp. between southeast of Iran and Pakistan.
Methods: From Jun 2020 to Dec 2020, 46 hydatid cysts were taken from human (n: 6), camel (n: 10), goat (n: 10), cattle (n: 10) and sheep (n: 10) in various cities of Sistan and Baluchestan Province of Iran, located at the neighborhood of Pakistan. DNA samples were extracted, amplified, and subjected to sequence analysis of cox1 and nad1 genes. Results: The phylogeny inferred by the Maximum Likelihood algorithm indicated that G1 genotype (n: 19), G3 genotype (n: 14) and G6 genotype (n: 13) assigned into their specific clades. The diversity indices showed a moderate (nad1: Hd: 0.485) to high hap- lotype diversity (cox1: Hd: 0.867) of E. granulosus s.s. (G1/G3) and low nucleotide diver- sity. The negative value of Tajima’s D and Fu’s Fs test displayed deviation from neutrali- ty indicating a recent population expansion. A parsimonious network of the haplotypes of cox1 displayed star-like features in the overall population containing IR9/PAK1/G1, IR2/PAK2/G3 and IR18/G6 as the most common haplotypes. A pairwise fixation index (Fst) indicated that E. granulosus s.s. populations are genetically moderate differen- tiated between southeast of Iran and Pakistan. The extension of haplotypes PAK18/G1 (sheep) and PAK26/G1 (cattle) toward Iranian haplogroup revealed that there is dawn of Echinococcus flow due to a transfer of alleles between mentioned populations through transport of livestock or their domestication.
Conclusion: The current findings strengthen our knowledge concerning the evolution- ary paradigms of E. granulosus in southeastern borders of Iran and is effective in control- ling of hydatidosis.