Molecular characterization of Echinococcus granulosus sensu lato genotypes circulating in small ruminants in north India

The etiological agents of cystic echinococcosis comprise a species complex, Echinococcus granulosus sensu lato (s. l.). Despite high endemicity, the disease remains neglected in most parts of the globe, including India. The present study aimed at investigating the genotypes of Echinococcus granulosus s. l. circulating in sheep and goats in two states (Haryana and Himachal Pradesh) and a union territory (Chandigarh) of north India. Out of 1049 slaughtered small ruminants (n = 314, 394, and 341 from Chandigarh, Himachal Pradesh, and Haryana, respectively), 85 (n = 53, 17, and 15 from Chandigarh, Himachal Pradesh, and Haryana, respectively) exhibited the presence of hydatid cysts. Based on the mitochondrial cox I and ATP6 genes, phylogeny, the population structure and haplotype network analyses were performed. Genotypes G1 and G3, and G6 corresponding to E. granulosus sensu stricto and E. canadensis, respectively, were recorded. Population structure analysis revealed a low nucleotide and high haplotype diversities for the present study isolates, emphasizing a recent population expansion. The perusal of literature revealed the present study to be the first to highlight small ruminants as intermediate hosts for the transmission of genotype G6 of E. granulosus s. l. in India.