Genetic characterization of zoonotic hookworms infecting wild felids in northern India

Hookworms are the most common soil-transmitted helminths that inhabit the small intestine of various domesticated and wild animals. Despite their conservation status, there is a paucity of research on hookworm infections in wild felids. This study aimed to investigate the prevalence of hookworm infections in wild felids in northern India and to genetically characterize the hookworms. Faecal samples (n = 96) from wild felids (lion, tiger, leopard, panther, jungle cat, and civet cat) were examined for helminthic infections. Samples positive for hookworms were subsequently subjected to molecular analysis targeting the internal transcribed spacer (ITS) region, followed by sequencing and phylogenetic analysis.

Among helminthic infections, Ancylostoma spp. ranked second (7.3%) after Toxocara cati (13.5%). Molecular analysis identified two species, A. caninum and A. ceylanicum. Phylogenetic analysis revealed distinct monophyletic clades for each species. Ancylostoma caninum formed a large clade with two subclades, one comprising Asian isolates and the other encompassing isolates from the Americas and Australia, whereas A. ceylanicum formed a single clade. Nucleotide identities ranged from 97.9 to 100% for A. caninum and from 99.1 to 100% for A. ceylanicum. Haplotype network analysis revealed eight haplotypes for A. caninum and six for A. ceylanicum. Genetic diversity correlated with geographic distance for A. caninum isolates, with Asian populations exhibiting high haplotype diversity but low nucleotide diversity. Neutrality indices suggested population stability for A. caninum and expansion for A. ceylanicum. Continent-wise analysis of molecular variance (AMOVA) indicated that 52.66% of the variation occurred within A. caninum populations, while 47.34% occurred between populations.

This study highlighted the genetic diversity and molecular epidemiology of hookworms in wild felids.