Prevalence and phylogeography of Taenia hydatigena metacestodes from goats of India

The study determined the prevalence and genetic population structure relationships of Cysticercus tenuicollis (Taenia hydatigena metacestode) retrieved from the goats slaughtered in north India. An overall prevalence of 9.62% (59/613) was recorded. Genetic population structure relationships were assessed by targeting partial cytochrome c oxidase subunit 1 mitochondrial gene sequence. Phylogenetic tree analysis revealed that all the present study representative isolates (n = 7) formed a major clade and grouped with T. hydatigena isolates retrieved from sheep, goats, pigs and dogs, originating from China, Iran, Nigeria, Ghana and Poland. However, a single isolate from Himachal Pradesh (isolate 3) formed a subgroup within the clade. The neutrality and diversity indices revealed high values of haplotype diversity [Hd = 0.99695 (0.95238-1.0000)] and low nucleotide diversity (pi = 0.49276), which was indicative of demographic expansion and low gene flow, suggesting that Indian T. hydatigena isolates were not genetically differentiated. Tajima's D (-1.26988) and Fu and Li's D statistics values (-0.74556) were negative, demonstrating deviations from neutrality and both propounded recent population expansion or purifying selection. Results highlighted a low genetic diversity of T. hydatigena metacestodes across the geographical range of north India.