Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India.
Department of Dermatology, Venerology & Leprology, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India.
Sci Rep. 2020 Jan 28;10(1):1297. doi: 10.1038/s41598-020-58187-0.
Dermatophytosis has gained interest in India due to rise in terbinafine resistance and difficulty in management of recalcitrant disease. The terbinafine resistance in dermatophytes is attributed to single nucleotide polymorphisms (SNPs) in squalene epoxidase (SE) gene. We evaluated the utility of amplified refractory mutation system polymerase chain reaction (ARMS PCR) for detection of previously reported point mutations, including a mutation C1191A in the SE gene in Trichophyton species. ARMS PCR was standardized using nine non-wild type isolates and two wild type isolates of Trichophyton species. Study included 214 patients with dermatophyte infection from March through December 2017. Antifungal susceptibility testing of isolated dermatophytes was performed according to CLSI-M38A2 guidelines. Among dermatophytes isolated in 68.2% (146/214) patients, Trichophyton species were predominant (66.4%). High (>2 mg/L, cut off) minimum inhibitory concentrations to terbinafine were noted in 15 (15.4%) Trichophyton mentagrophytes complex isolates. A complete agreement was noted between ARMS PCR assay and DNA sequencing. C to A transversion was responsible for amino acid substitution in 397 position of SE gene in terbinafine resistant isolates. Thus, the ARMS PCR assay is a simple and reliable method to detect terbinafine-resistant Trichophyton isolates.
在印度，由于特比萘芬耐药性的增加和顽固性疾病的治疗困难，皮肤癣菌病引起了人们的兴趣。皮肤癣菌中的特比萘芬耐药性归因于角鲨烯环氧化酶（SE）基因中的单核苷酸多态性（SNP）。我们评估了扩增难治性突变系统聚合酶链反应（ARMS-PCR）检测先前报道的点突变的效用，包括 SE 基因中 Trichophyton 种的突变 C1191A。使用 9 个非野生型分离株和 2 个 Trichophyton 种的野生型分离株对 ARMS-PCR 进行了标准化。该研究包括 2017 年 3 月至 12 月期间的 214 例皮肤癣菌感染患者。根据 CLSI-M38A2 指南对分离的皮肤癣菌进行了抗真菌药敏试验。在 68.2%（146/214）患者中分离出的皮肤癣菌中， Trichophyton 种占优势（66.4%）。在 15 株（15.4%） Trichophyton mentagrophytes 复合体分离株中，最低抑菌浓度（MIC）值高于 2mg/L（截止值）。ARMS-PCR 检测与 DNA 测序完全一致。C 到 A 的颠换导致特比萘芬耐药分离株 SE 基因 397 位氨基酸取代。因此，ARMS-PCR 检测是检测特比萘芬耐药性 Trichophyton 分离株的一种简单可靠的方法。
