Inactivation of pathogenic dermatophytes by ultraviolet irradiation in swimming pool thermal water

Abstract

The effect of ultraviolet (UV) radiation from low-pressure mercury lamp against some pathogenic dermatophytes species such as Epidermophyton floccosum, Trichophyton mentagrophytes, Trichophyton rubrum, Trichophyton schoenleinii, Trichophyton tonsurans and Trichophyton violaceum suspended in thermal water was evaluated in laboratory-scale condition at various times. The main results showed that within 120 s of exposure, all species of dermatophytes are completely inactivated, which was evidenced by the absence of fungal regrowth, while after 60 s only T. tonsurans was recovered, with a reduction of 3.28 log. Shorter exposure times were not enough to completely inactivate all dermatophytes species. The samples treated with UV radiation for 120 s did not give evidence of fungal regrowth indicating that this disinfectant action is persistent over time. In conclusion, UV radiation can be proposed to reduce the risk of infection by dermatophytes eventually present in swimming pools that use thermal water.

Ultraviolet germicidal irradiation in tap water contaminated by Aspergillus spp.

“…The latter species are no longer detectable after 40 s of exposure time. In our previous study we found comparable effectiveness of UV radiation for the disinfection of swimming pool thermal water contaminated by dermatophyte fungi [ 34 ].…”

Dermatophyte infections in environmental contexts

“…It has been reported from the Middle East [36], Japan [31], Europe [30,34], Latin America [37] and many other places.…”

Protection of Public Health from Microbial and Chemical Hazards in Swimming Pool Environments

“…However, different fungal species require a different UV dose. The fungal species in the dermatophyte group, Epidermophyton floccosum, Trichophyton violaceum, Trichophyton schoenleinii, and Trichophyton mentagrophytes are more susceptible to UV than other dermatophytes such as Trichophyton tonsurans and Trichophyton rubrum (Sisti et al, 2014). A UV dose of 48 mJ/cm² was required to achieve 1.71 and 2.4 log removal of Trichophyton tonsurans and Trichophyton rubrum, respectively.…”