Abstract
Trichophyton erinaceiis a maincause ofdermatophytosis in hedgehogsand is increasinglyreported fromhuman infections worldwide.It is found in wild European hedgehogs ( Erinaceus europaeus ) but also in the African four-toed hedgehog ( Atelerix albiventris ) , a popular pet animal worldwide. Little is known about the taxonomy and population genetics of this pathogen despite its increasing importance in clinical practice.
Notably, whether there are different populations or even cryptic species associated with different hosts or geographic regions is not known. To answer these questions, we collected 161 isolates, per- formed phylogenetic and population-genetic analyses, determined mating type, and characterized morphology and physiology.
Multigene phylogeny and microsatellite analysis supported T. erinacei as a monophyletic species, in contrast to highly incon- gruent single-gene phylogenies. Two main subpopulations, one specific mainly to Atelerix and the second to Erinaceus hosts, were identified inside T. erinacei , and slight differences in the size of microconidia and antifungal susceptibilities were observed among them.Although the process of speciation into two lineages is ongoing in T.erinacei ,there is still gene flow between these populations.
Thus, we present T. erinacei as a single species, with notable intraspecies variability in genotype and phenotype. The data from wild hedgehogs indicated that sexual reproduction in T. erinacei and de novo infection of hedgehogs from soil are probably rare events and that clonal horizontal spread strongly dominates.
The molecular typing approach used in this study represents a suitable tool for further epidemiological surveillance of this emerging pathogen in both animals and humans. The results of this study also highlighted the need to use a multigene phylogeny ideally in combination with other independent molecular markers to understand the species boundaries of dermatophytes.