Zoonotic dermatophyte Trichophyton erinacei in pet hedgehogs: sampling methodology and further insight into genetic diversity.

Trichophyton erinacei is a zoonotic dermatophyte, typically associated with hedgehogs. While the European hedgehog (Erinaceus europaeus) is a frequent host in the wild, the African pygmy hedgehog (Atelerix albiventris) is increasingly affected in captive settings. Despite carrying the fungus, most hedgehogs remain asymptomatic, which complicates early detection and increases the risk of transmission to other animals or humans. This study addresses the difficulty of sampling from asymptomatic individuals and the need for understanding the genetic variation of T. erinacei. Three non-invasive sampling techniques (interdental brushes, cotton swabs, and toothbrushes) were used to collect skin samples from 103 captive A. albiventris individuals in the Czech Republic and Romania. Other materials, such as spines or crusts, were also collected. Samples were cultured on selective media (SDA with cycloheximide and chloramphenicol), and isolates were identified by ITS rDNA region sequencing. Genetic variation was assessed using multilocus microsatellite typing. Out of 103 sampled African pygmy hedgehogs, 24.3% (25/103) tested positive for T. erinacei, of which 76.0% (19/25) were asymptomatic. No other dermatophyte species were isolated from tested hedgehogs. Among different sampling techniques, interdental brushes showed the highest detection rate (80%), significantly outperforming cotton swabs and toothbrushes. ITS rDNA region sequencing and multilocus microsatellite typing revealed no genetic variation among the isolates, indicating low intraspecific diversity in T. erinacei from captive A. albiventris. Our results emphasize the importance of reliable, non-invasive sampling methods for early diagnosis, particularly in the context of rising numbers of hedgehogs kept as pets. It also demonstrates the superior effectiveness of interdental brushes over other sampling techniques for detecting T. erinacei in hedgehogs, offering a practical improvement for pathogen surveillance. The absence of genetic variability suggests the circulation of a single clone M1 in the captive population.