Journal Article
Clinical and Mycological Profiles of Chronic and Recalcitrant Dermatophytosis: Türkiye, 2022–2024
Murat Durdu; Hazal Kandemir; Ayşe Sultan Karakoyun; Pavlína Lysková; Daniela Kolarczyková; Oğuzhan Bingöl; Yasemin Erdem; Funda Aktürk-Gözel; Özlem Su-Küçük; Melisa Özay; Aslan Yürekli; İlayda Muslu; İsa An; Sinan Özçelik; Tuğba Falay-Gür; Tuğba Tehçi; Abdullah Demirbaş; Gözde Ulutaş-Demirbaş; Tuğba Atak; Kaan Taşolar; Büşra Acar-Mantar; Mehmet Kamil Mülayim; Rebiay Kıran; Ayşe Tülin Mansur; İrem Yanatma; Sertaç Sever; Yeşim Yayla-Öztürk; Selami Aykut Temiz; Rabia Öztaş-Kara; Fatma Uzun; Ferit Kuşçu; Gonca Erköse-Genç; Zayre Erturan; Sybren de Hoog; Vit Hubka; Macit Ilkit
Mycopathologia · Vol. 191, Issue 2 · 2026
Abstract
This study investigated the treatment outcomes of 91 patients with chronic and recalcitrant dermatophytosis from 20 hospitals in Türkiye between June 2022 and March 2024, as well as the in vitro antifungal susceptibility and squalene epoxidase ( SQLE ) substitution profiles of the dermatophytes obtained from these patients. Molecular identification by sequencing 91 isolates, revealed 76 Trichophyton mentagrophytes ITS genotype VIII (TmVIII; also known as T . indotineae ) isolates, 13 Trichophyton rubrum , one Trichophyton tonsurans , and one Microsporum canis . The Phe397Leu substitution predominated in the SQLE , and Tyr414His co-occurred in nine TmVIII isolates. Five novel substitutions were observed in TmVIII. Among 13 T . rubrum isolates, three showed different SQLE substitution patterns compared to the wild-type strain. EUCAST antifungal susceptibility testing revealed high minimum inhibitory concentrations (MICs) for terbinafine (TRB) (> 0.25 mg/L) and for fluconazole (FLZ) (≥ 16 mg/L), indicating resistance in most TmVIII isolates. Of the 91 patients, 83 responded to FLZ, itraconazole (ITZ), TRB, or voriconazole-based regimens. While adjunct therapy with FLZ and resveratrol (RES) led to improvement in 28/29 patients despite their high in vitro inhibition concentrations, ITZ and curcumin (CUR) therapy was successful in 3/3 patients. However, the in vitro efficiency of CUR could not be evaluated. These findings highlight the local occurrence of specific SQLE substitutions, underscore the importance of EUCAST MIC testing combined with SQLE sequencing for surveillance, and support further evaluation of RES and CUR as an adjunct in TRB-resistant TmVIII.