<i>Trichophyton mentagrophytes</i> Internal Transcribed Spacer Genotype VIII

Caplan, Arthur; Zakhem, George A.; Pomeranz, Miriam Keltz

doi:10.1001/jamadermatol.2023.2645

Cited by 5 publications

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“…Although T . indotineae —a new emerging species associated widespread and recalcitrant dermatophytosis—has been detected in the United States, 29,30 its clinical significance in onychomycosis management is unclear as it is disproportionately identified in skin specimens 12,13,31 …”

Section: Discussionmentioning

confidence: 99%

Potential emergence of terbinafine resistance by squalene epoxidase gene mutations: An 18‐month cohort study of onychomycosis patients in the United States

Gupta,

Wang,

Polla Ravi

et al. 2024

Mycoses

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BackgroundThere is a concerning rise in antifungal‐resistant dermatophytosis globally, with resistance to terbinafine conferred by point mutations in the squalene epoxidase (SQLE) gene.ObjectivesReport changes in the prevalence and profile of SQLE mutations in onychomycosis patients in the United States.MethodsA longitudinal cohort study of toenail samples was collected from suspected onychomycosis patients over an 18‐month period from 2022 to 2023. Samples were submitted from across the United States and subjected to multiplex real‐time polymerase chain reactions for dermatophyte detection, with further screening of SQLE mutations at four known hotspots (393Leu, 397Phe, 415Phe and 440His).ResultsA total of 62,056 samples were submitted (mean age: 57.5 years; female: 60.4%). Dermatophytes were detected in 38.5% of samples, primarily Trichophyton rubrum complex (83.6%) and T. mentagrophytes complex (10.7%). A survey of SQLE mutations was carried out in 22,610 dermatophyte samples; there was a significant increase in the prevalence of SQLE mutations between the first quarter of 2022 and the second quarter of 2023 (29.0 to 61.9 per 1000 persons). The Phe397Leu substitution was the predominant mutation; Phe415Ser and His440Tyr have also emerged which were previously reported as minor mutations in skin samples. The temporal change in mutation rates can be primarily attributed to the Phe415Ser substitution. Samples from elderly patients (>70 years) are more likely to be infected with the T. mentagrophytes complex including strains harbouring the Phe415Ser substitution.ConclusionThe prevalence of SQLE mutations among onychomycosis patients with Trichophyton infections may be underestimated. Older individuals may have a higher risk.

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Section: Discussionmentioning

confidence: 99%

Potential emergence of terbinafine resistance by squalene epoxidase gene mutations: An 18‐month cohort study of onychomycosis patients in the United States

Gupta,

Wang,

Polla Ravi

et al. 2024

Mycoses

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“…We applaud Caplan et al for their comprehensive and timely case series and for the remarkable clinical–public health collaboration it represents. This report has important implications for clinicians and public health practitioners.…”

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confidence: 97%

“…First described as a unique species in the past decade, T indotineae (previously called Trichophyton mentagrophytes genotype VIII ) has caused outbreaks of tinea—often extensive, pruritic, and frequently resistant to first-line antifungals—primarily in South Asia but also in Europe, Canada, Australia, and Asia . The first 3 cases of T indotineae dermatophytosis in the US were reported in 2023, and a fourth case—possibly sexually transmitted—was reported in 2024 …”

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confidence: 99%

“…A case series in this issue of JAMA Dermatology describes 11 more T indotineae infections in New York City from May 2022 to May 2023 . The case series included 5 female and 6 male patients, with a median (range) age of 39 (8-64) years.…”

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confidence: 99%

“…It should also arise in instances of nonresponse to typical first-line topical antifungals (including combination antifungal-corticosteroid topicals) and/or oral antifungals, given the emergence of resistance T indotineae (and other dermatophytes) . Additionally, epidemiologic risk factors, such as travel to South Asia or contact with persons with known or suspected dermatophytosis, should prompt suspicion …”

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confidence: 99%

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Resistant Trichophyton indotineae Dermatophytosis—An Emerging Pandemic, Now in the US

Bui,

Katz

2024

JAMA Dermatol

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Fungus is finding 15 minutes of fame.A variant Ophiocordyceps unilateralis, a real-life fungus, took a fictional star turn in 2023 as the culprit behind a civilization-threatening zombie pandemic in HBO's blockbuster series, The Last of Us. Increasing infections with Candida auris-a fungus resistant to many antifungal medicines, often acquired in health care settings, and frequently fatal-have prompted the US Centers for Disease Control and Prevention (CDC) to label that fungus a "serious global health threat." 1 Psilocybin, the psychoactive substance found in magic mushrooms, is gaining attention for its potential to treat depression and other psychiatric conditions. 2 And now: Trichophyton indotineae. This dermatophyte is, almost literally, on steroids; experts have linked its emergence to inappropriate use of combination topical products containing antifungals and high-potenc y corticosteroids. [3][4][5] First described as a unique species in the past decade, 6 T indotineae (previously called Trichophyton mentagrophytes genotype VIII) has caused outbreaks of tinea-often extensive, pruritic, and frequently resistant to first-line antifungalsprimarily in South Asia but also in Europe, Canada, Australia, and Asia. 4,5 The first 3 cases of T indotineae dermatophytosis in the US were reported in 2023, 7,8 and a fourth casepossibly sexually transmitted-was reported in 2024. 9 A case series in this issue of JAMA Dermatology describes 11 more T indotineae infections in New York City from May 2022 to May 2023. 10 The case series included 5 female and 6 male patients, with a median (range) age of 39 (8-64) years. Only 1 was immunocompromised and had untreated lymphoma. Nine had traveled to Bangladesh within 2 years prior to rash onset; 4 of those patients also had contact with a family member or partner with T indotineae infection. One patient had neither traveled internationally nor had contact with an infected person, to their knowledge. Epidemiologic exposures were not available for 1 patient.All patients experienced widespread rash, most commonly involving the trunk, extremities, groin, and buttocks; 2 patients had facial involvement. Nine patients reported pruritus.Delays in diagnosis were substantial, with a median (range) of 10 (3-42) months. Prior to diagnosis, 6 patients were treated with topical corticosteroids, including 2 with combination antifungal-corticosteroid topicals. All patients unsuccessfully tried treatment with at least 1 topical antifungal medicine. Except for 1 patient who was initially treated with itraconazole, all patients were unsuccessfully treated with at least

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Mapping the Global Spread of T. indotineae: An Update on Antifungal Resistance, Mutations, and Strategies for Effective Management

Gupta,

Polla Ravi,

Wang

et al. 2024

Mycopathologia

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Trichophyton mentagrophytes Internal Transcribed Spacer Genotype VIII

Abstract: This case report describes large, annular, scaly, and erythematous plaques in the axillae and legs extending from the groin as well as involvement of the chest surrounding the areola.

Cited by 5 publications

References 5 publications

Potential emergence of terbinafine resistance by squalene epoxidase gene mutations: An 18‐month cohort study of onychomycosis patients in the United States

Potential emergence of terbinafine resistance by squalene epoxidase gene mutations: An 18‐month cohort study of onychomycosis patients in the United States

Resistant Trichophyton indotineae Dermatophytosis—An Emerging Pandemic, Now in the US

Mapping the Global Spread of T. indotineae: An Update on Antifungal Resistance, Mutations, and Strategies for Effective Management

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