The complete mitochondrial genome of Tunga penetrans and insights into flea phylogeny
Tungiasis, one of the oldest and most neglected tropical diseases endemic to sub-Saharan Africa and the Americas, is caused by the female parasitic flea, Tunga penetrans. The flea burrows into the skin, leading to acute and chronic inflammation, often exacerbated by bacterial superinfection. Despite its significant public health impact, genomic studies on T. penetrans are scarce. Here, we present the first complete mitochondrial genome of T. penetrans, comprising 17,279 base pairs and encoding 13 protein-coding genes, 22 transfer RNAs and 2 ribosomal RNAs. Phylogenetic analysis of the cox2 gene revealed a divergent basal lineage from Brazil, supporting a South American origin of T. penetrans and highlights genetic differentiation within the Americas. Clustering of the Ecuadorian and African isolates further suggests historical connections, likely linked to transatlantic maritime trade. The tree highlights a strong South American origin and evidence of migration and diversification, facilitated by human and animal movement. Phylogenetic analysis of the complete genomes relying on the protein-coding genes of other fleas revealed that T. penetrans is closely related to Dorcadia ioffi, a semi-sessile flea of goats and sheep in China. This mitochondrial genome provides a critical resource for future studies on molecular epidemiology, evolutionary history, and control of tungiasis.