Molecular detection of Fonsecaea pedrosoi in Rhipicephalus sanguineus and Rhipicephalus microplus ticks from Venezuela.

Chromoblastomycosis, caused primarily by Fonsecaea pedrosoi, is traditionally associated with traumatic environmental inoculation. We analyzed 50 Rhipicephalus sanguineus/R. microplus ticks from chromoblastomycosis-endemic Venezuelan states (Lara and Portuguesa) using Oxford Nanopore amplicon sequencing. Remarkably, F. pedrosoi dominated the tick eukaryotic microbiome, comprising 78% and 75% of fungal communities in Lara and Portuguesa, respectively. This unexpected high abundance across geographically distinct endemic foci suggests a previously unrecognized ecological association between ticks and the pathogen. While environmental transmission remains established, these findings provide first molecular evidence of F. pedrosoi in tick microbiomes, warranting investigation into potential carrier, vector or reservoir roles that may reshape chromoblastomycosis epidemiology understanding.