TY - JOUR
T1 - Increasing Terbinafine Resistance in Danish Trichophyton Isolates 2019-2020
AU - Astvad, Karen Marie Thyssen
AU - Hare, Rasmus Krøger
AU - Jørgensen, Karin Meinike
AU - Saunte, Ditte Marie Lindhardt
AU - Thomsen, Philip Kjettinge
AU - Arendrup, Maiken Cavling
PY - 2022/1/31
Y1 - 2022/1/31
N2 - Terbinafine resistance in Trichophyton species has emerged and appears to be increasing. A new EUCAST susceptibility testing method and tentative ECOFFs were recently proposed for Trichophyton. Terbinafine resistance and target gene mutations were detected in 16 Danish isolates in 2013-2018. In this study, samples/isolates submitted for dermatophyte susceptibility testing 2019-2020 were examined. Species identification (ITS sequencing for T. mentagrophytes/T. interdigitale species complex (SC) isolates), EUCAST MICs and squalene epoxidase (SQLE) profiles were obtained. Sixty-three isolates from 59 patients were included. T. rubrum accounted for 81% and T. mentagrophytes/T. interdigitale SC for 19%. Approximately 60% of T. rubrum and T. mentagrophytes/interdigitale SC isolates were terbinafine non-wildtype and/or had known/novel SQLE mutations with possible implications for terbinafine MICs. All infections with terbinafine-resistant T. mentagrophytes/interdigitale SC isolates were caused by Trichophyton indotineae. Compared to 2013-2018, the number of patients with terbinafine-resistant Trichophyton isolates increased. For T. rubrum, this is partly explained by an increase in number of requests for susceptibility testing. Terbinafine-resistant T. indotineae was first detected in 2018, but accounted for 19% of resistance (4 of 21 patients) in 2020. In conclusion, terbinafine resistance is an emerging problem in Denmark. Population based studies are warranted and susceptibility testing is highly relevant in non-responding cases.
AB - Terbinafine resistance in Trichophyton species has emerged and appears to be increasing. A new EUCAST susceptibility testing method and tentative ECOFFs were recently proposed for Trichophyton. Terbinafine resistance and target gene mutations were detected in 16 Danish isolates in 2013-2018. In this study, samples/isolates submitted for dermatophyte susceptibility testing 2019-2020 were examined. Species identification (ITS sequencing for T. mentagrophytes/T. interdigitale species complex (SC) isolates), EUCAST MICs and squalene epoxidase (SQLE) profiles were obtained. Sixty-three isolates from 59 patients were included. T. rubrum accounted for 81% and T. mentagrophytes/T. interdigitale SC for 19%. Approximately 60% of T. rubrum and T. mentagrophytes/interdigitale SC isolates were terbinafine non-wildtype and/or had known/novel SQLE mutations with possible implications for terbinafine MICs. All infections with terbinafine-resistant T. mentagrophytes/interdigitale SC isolates were caused by Trichophyton indotineae. Compared to 2013-2018, the number of patients with terbinafine-resistant Trichophyton isolates increased. For T. rubrum, this is partly explained by an increase in number of requests for susceptibility testing. Terbinafine-resistant T. indotineae was first detected in 2018, but accounted for 19% of resistance (4 of 21 patients) in 2020. In conclusion, terbinafine resistance is an emerging problem in Denmark. Population based studies are warranted and susceptibility testing is highly relevant in non-responding cases.
UR - http://www.scopus.com/inward/record.url?scp=85123749596&partnerID=8YFLogxK
U2 - 10.3390/jof8020150
DO - 10.3390/jof8020150
M3 - Journal article
C2 - 35205904
SN - 2309-608X
VL - 8
SP - 1
EP - 12
JO - Journal of fungi (Basel, Switzerland)
JF - Journal of fungi (Basel, Switzerland)
IS - 2
M1 - 150
ER -