Diagnostic ability of Peptidase S8 gene in the Arthrodermataceae causing dermatophytoses: A metadata analysis.

An unambiguous identification of dermatophytes causing dermatophytoses is necessary for accurate clinical diagnosis and epidemiological implications. In the current taxonomy of the Arthrodermataceae, the etiological agents of dermatophytoses consist of seven genera and members of the genera Trichophyton are the most prevalent etiological agents at present. The genera Trichophyton consists of 16 species that are grouped as clades, but the species borderlines are not clearly delimited. The aim of the present study was to determine the discriminative power of subtilisin gene variants (SUB1-SUB12) in family Arthrodermataceae, particularly in Trichophyton. Partial and complete reads from 288 subtilisin gene sequences of 12 species were retrieved and a stringent filtering following two different approaches for analysis (probability of correct identification (PCI) and gene gap analysis) conducted to determine the uniqueness of the subtilisin gene subtypes. SUB1 with mean PCI value of 60% was the most suitable subtilisin subtype for specific detection of T.rubrum complex, however this subtype is not reported in members of T. mentagrophytes complex which is one of the most prevalent etiological agent at present. Hence, SUB7 with 40% PCI value was selected for testing its discriminative power in Trichophyton species. SUB7 specific PCR based detection of dermatophytes was tested for sensitivity and specificity. Sequences of SUB7 from 42 isolates and comparison with the ITS region showed that differences within the subtilisin gene can further be used to differentiate members of the T. mentagrophytes complex. Further, subtilisin cannot be used for the differentiation of T. benhamiae complex since all SUB subtypes show low PCI scores. Studies on the efficiency and limitations of the subtilisin gene as a diagnostic tool are currently limited. Our study provides information that will guide researchers in considering this gene for identifying dermatophytes causing dermatophytoses in human and animals.

Knowledge, practice, and infection status of prisoners toward dermatomycosis: a study in Nepal.

Background: Dermatophytosis, commonly known as tinea, poses a significant public health concern worldwide, especially in environments with poor hygiene and overcrowding, such as prisons. Despite its prevalence and impact on quality of life, there is a lack of research on the knowledge and hygiene practices regarding dermatophytosis among prisoners, particularly in Nepal. Objective: The study aimed to assess prisoners' knowledge, hygiene practice and infection status regarding dermatophytosis in Central Prison, Nepal. Methods: A descriptive cross-sectional study with a sample size of 184 respondents was designed to collect data using a validated pre-tested questionnaire from September 2023 to January 2024. The collected data was then analyzed using IBM SPSS version 21. Knowledge and hygiene practices were measured on an eight and 11-point scale and rated as poor (≤4) and sound (>4), bad (≤6), and good (>6), respectively. Summary data were presented by descriptive, while Chi-square and logistic regression were used for inferential statistics at p < 0.05. Results: The findings revealed moderate knowledge among prisoners regarding dermatophytosis, with significant gaps in understanding its spread and prevention. While most prisoners recognized the importance of treatment, there were misconceptions about the inevitability of contracting dermatophytosis and the role of personal hygiene. Conclusion: Despite good knowledge levels, adherence to recommended hygiene practices was suboptimal, highlighting the need for targeted interventions. The study underscores the importance of addressing knowledge gaps, changing attitudes, and promoting hygienic practices to mitigate the burden of dermatophytosis among prisoners.

Dual quantitative PCR assays for the rapid detection of Trichophyton indotineae from clinical samples.

Trichophyton indotineae is an emerging species of the Trichophyton mentagrophytes complex (TMC), responsible for an epidemic of widespread hairless skin infections that is frequently (50-70%) resistant to terbinafine. In order to initiate appropriate treatment as quickly as possible without waiting for culture positivity (10-15 days) and molecular identification from the strain, we developed a dual quantitative PCR (qPCR) for the direct detection of T. indotineae in clinical samples. We first designed a T. indotineae-specific qPCR assay (TI-qPCR) targeting a single specific polymorphism in the internal transcribed spacer region. Although none of the 94 non-dermatophyte and 7 dermatophyte species were amplified, this TI-qPCR allowed amplification of other TMC species at a lower yield. With equal amounts (0.1 ng) of DNA per reaction, the mean quantitative cycle (Cq) values for T. indotineae and non-indotineae TMC were 27.9 (±0.1) and 38.9 (±0.3), respectively. Therefore, we normalized this assay against a previously validated pan-dermatophyte qPCR assay (PD-qPCR) and relied on the ΔCq [(TI-qPCR) - (PD-qPCR)] to identify T. indotineae versus other TMC species. Dual assay was validated using 86 clinical samples of culture-confirmed T. indotinea and 19 non-indotineae TMC cases. The mean ΔCq for non-indotineae TMC was 9.6 ± 2.7, whereas the ΔCq for T. indotinea was -1.46 ± 2.1 (P < .001). Setting the ΔCq at 4.5 as a cutoff value resulted in 100% specificity for the detection of T. indotineae. This dual qPCR assay quickly detects T. indotineae from skin scrapings, aiding in early diagnosis and treatment for patients with suspected infection.

Identifying the emerging species Trichophyton indotineae is long and requires to wait for culture positivity. We developed a dual qPCR strategy to detect T. indotineae directly from clinical sample with a 100% sensitivity.

Epidemiological trends, antifungal drug susceptibility and SQLE point mutations in etiologic species of human dermatophytosis in Al-Diwaneyah, Iraq.

Dermatophytes show a wide geographic distribution and are the main causative agents of skin fungal infections in many regions of the world. Recently, their resistance to antifungal drugs has led to an obstacle to effective treatment. To address the lack of dermatophytosis data in Iraq, this study was designed to investigate the distribution and prevalence of dermatophytes in the human population and single point mutations in squalene epoxidase gene (SQLE) of terbinafine resistant isolates. The identification of 102 dermatophytes isolated from clinical human dermatophytosis was performed through morphological and microscopic characteristics followed by molecular analysis based on ITS and TEF-1α sequencing. Phylogeny was achieved through RAxML analysis. CLSI M38-A2 protocol was used to assess antifungal susceptibility of the isolates to four major antifungal drugs. Additionally, the presence of point mutations in SQLE gene, which are responsible for terbinafine resistance was investigated. Tinea corporis was the most prevalent clinical manifestation accounting for 37.24% of examined cases of dermatophytosis. Based on ITS, T. indotineae (50.98%), T. mentagrophytes (19.61%), and M. canis (29.41%) was identified as an etiologic species. T. indotineae and T. mentagrophytes strains were identified as T. interdigitale based on TEF-1α. Terbinafine showed the highest efficacy among the tested antifungal drugs. T. indotineae and T. mentagrophytes showed the highest resistance to antifungal drugs with MICs of 2-4 and 4 µg/mL, while M. canis was the most susceptible species. Three of T. indotineae isolates showed mutations in SQLE gene Phe397Leu substitution. A non-previously described point mutation, Phe311Leu was identified in T. indotineae and mutations Lys276Asn, Phe397Leu and Leu419Phe were diagnosed in T. mentagrophytes XVII. The results of mutation analysis showed that Phe397Leu was a destabilizing mutation; protein stability has decreased with variations in pH, and point mutations affected the interatomic interaction, resulting in bond disruption. These results could help to control the progression of disease effectively and make decisions regarding the selection of appropriate drugs for dermatophyte infections.

Exploring treatment and antifungal resistance in an outbreak of tinea caused by Microsporum audouinii.

BACKGROUND: Microsporum audouinii has resurged recently. Infections with the dermatophyte are difficult to treat, which raises the question if we treat M. audouinii infections with the most effective antifungal (AF) agent. OBJECTIVES: The aims of this study was to investigate an outbreak of tinea capitis (TC) in Denmark, address the challenges in outbreak management and to conduct two reviews regarding previous outbreaks and minimal inhibitory concentration (MIC). METHODS: We used Wood's light, culture, direct microscopy, and PCR for screening and antifungal susceptibility testing (AFST) for treatment optimization. We performed two reviews to explore M. audouinii outbreaks and MIC values using broth microdilution method. RESULTS: Of 73 screened individuals, 10 had confirmed M. audouinii infections. Clinical resistance to griseofulvin was observed in 4 (66%) cases. While previous outbreaks showed high griseofulvin efficacy, our study favoured terbinafine, fluconazole and itraconazole in our hard-to-treat cases. AFST guided the choice of AF. Through the literature search, we identified five M. audouinii outbreaks, where differences in management included the use of Wood's light and prophylactic topical AF therapy. Terbinafine MIC values from the literature ranged from 0.002 to 0.125 mg/L. CONCLUSION: Use of Wood's light and preventive measurements were important for limiting infection. The literature lacked MIC data for griseofulvin against M. audouinii, but indicated sensitivity for terbinafine. The clinical efficacy for M. audouinii treatment was contradictory favouring both terbinafine and griseofulvin. AFST could have a key role in the treatment of difficult cases, but lack of standardisation of AFST and MIC breakpoints limits its usefulness.

Potential Sexual Transmission of Tinea Pubogenitalis From TMVII.

This case report describes a patient with Trichophyton mentagrophytes internal transcribed spacer genotype VII resulting in tinea genitalis, glutealis, and corporis.

Terbinafine-resistant T. indotineae due to F397L/L393S or F397L/L393F mutation among corticoid-related tinea incognita patients.

Tinea incognita (TI) can mimic other dermatoses, presenting a diagnostic challenge for dermatologists. In some uncertain cases, it is crucial to accurately identify the causative agent using internal transcribed spacer (ITS) sequencing. The global issue of drug-resistant dermatophytosis is increasing, with Trichophyton (T.) indotineae being the main cause. This study presents four cases of TI (diagnosed as eczema) by terbinafine-resistant T. indotineae strains and reviews the current global TI epidemiology based on geographical continent and related conditions. Furthermore, squalene epoxidase (SQLE)-associated resistance mechanisms are evaluated. Lesions caused by terbinafine-resistant T. indotineae strains do not respond to allylamine antifungals, thus allowing the infection to spread. Among T. indotineae isolates, the SQLE F397L substitution is the most prevalent mutation contributing to azole resistance. F397L and L393F replacements in SQLE were detected in all isolates that exhibited high-level resistance. L393S was seen in isolates with low-resistant strains. Interestingly, and for the first time, an L393F amino acid substitution in the SQLE gene product was detected in the Iranian clinical T. indotineae strain. Also, a genomics-based update on terbinafine resistance that focuses on T. indotineae is discussed in this study.

A survey of 701 cases of tinea faciei in Hangzhou, southeastern China, from 2018 to 2023.

BACKGROUND: Tinea faciei, a specific dermatophytosis that affects the glabrous skin of the face, not only causes physical discomfort but also leads to greater psychological distress. Tinea faciei is a public health concern. OBJECTIVES: To analyse the epidemiological characteristics, responsible dermatophyte species and clinical features of tinea faciei in Hangzhou. METHODS: Data were obtained from the Laboratory Information System of the Mycology Laboratory and Medical Information System at a hospital in Hangzhou. Isolates were identified based on their macroscopic appearance and microscopic morphology. RESULTS: Tinea faciei was diagnosed in 701 patients, involving 359 males and 342 females, aged between 2 months and 97 years. In total, 499 isolates (71.18%) were identified as Trichophyton rubrum. Anthropophilic isolates were identified in 297 (82.73%) males and 207 (60.53%) females (p < .01). Among patients with anthropophilic dermatophytes infection, 447 (88.69%) were adults. Zoophilic dermatophytes were isolated in 57 (15.88%) males and 130 (38.01%) females (p < .01), among whom 108 (57.75%) were children. CONCLUSIONS: Anthropophilic dermatophytes, especially T. rubrum, were the predominant cause of tinea faciei, while zoophilic dermatophytes were the most prevalent in children. Compared with men, women may be more susceptible to zoophilic dermatophytes.

Common Skin Conditions in Children and Adolescents: Nonbacterial Infections.

Tinea infections are caused by dermatophytes, except for tinea versicolor, which is caused by yeasts in the Malassezia genus. If available, potassium hydroxide preparation should be performed to confirm diagnosis of tinea capitis or onychomycosis. In some cases, fungal culture, UV light examination, or periodic acid-Schiff stain can be helpful. Topical drugs are effective for tinea corporis, tinea cruris, and tinea pedis. Tinea incognito is an atypical presentation that usually requires systemic treatment. Management of tinea capitis always requires oral drugs. Oral drugs are preferred for onychomycosis treatment but should not be prescribed without confirmation of fungal infection. Localized cases of tinea versicolor can be managed with topical drugs, but oral drugs might be needed for severe, widespread, or recurrent cases. Warts are superficial human papillomavirus infections. Common treatments include irritant, destructive (eg, cryotherapy), immune stimulant (eg, intralesional Candida antigen), and debridement and excision methods. Scabies infestation results in intensely itchy papules, nodules, or vesicles. Mites and burrows on the skin are pathognomonic but difficult to identify. Dermoscopy, particularly with UV light, can make identification easier. Topical permethrin and oral ivermectin are two of the most commonly used treatments. All household and close contacts should be treated regardless of the presence or absence of symptoms.

Tinea faciei clinical characteristics, causative agents, treatments and outcomes; a retrospective study in Thailand.

BACKGROUND: Tinea faciei is a relatively uncommon dermatophyte infection. The studies, which included clinical forms, and isolated species of dermatophytes, are limited. MATERIALS AND METHODS: This retrospective study aims to determine the causative organism, clinical characteristics, treatments and outcomes of patients with tinea faciei attending the dermatologic clinic, Siriraj Hospital, from 1 January 2017 to 30 September 2021. Demographic data, clinical presentations, isolated dermatophyte species, treatments and outcomes were collected and analysed. RESULTS: A total of 151 tinea faciei cases were observed. Trichophyton rubrum (48.6%), Trichophyton mentagrophytes complex (22.2%) and Microsporum canis (18.1%) were common causative agents. Tinea faciei was commonly detected in females (64.9%) with a history of pets (54.6%). Clinical presentations often involved plaques and scales on the cheeks. Among patients with lesions on the cheek, mycological cure was observed significantly less often compared to those without cheek lesions. Patients with other concurrent skin or nail infections, a history of topical steroids and a history of previous fungal infection had a slightly longer duration of mycological cure than those without factors. Recurrent infection was found in 33.3%. Male, history of previous fungal infection, and lesions on the cheeks were significantly associated with recurrent infection. CONCLUSIONS: Fungal infection of the face was commonly found in women and patients with pets. The most common pathogen that caused tinea faciei was T. rubrum. Topical antifungal treatments could be used with favourable outcomes. The history of past infection and lesion on the cheeks should be carefully assessed to be vigilant for recurrent infection.

High Prevalence of Terbinafine Resistance Among Trichophyton mentagrophytes/T. interdigitale Species Complex, a Cross-Sectional Study from 2021 to 2022 in Northern Parts of Iran.

Treatment-resistant dermatophytosis caused by the members of the Trichophyton mentagrophytes/Trichophyton interdigitale species group (TMTISG) is increasing worldwide. We aimed to determine the prevalence of TMTISG in patients with dermatophytosis in two centers from north of Iran and detect the possible mutations in the squalene epoxidase (SQLE) gene in relevant terbinafine (TRB) resistant pathogenic isolates. From November 2021 to December 2022, 1960 patients suspected to dermatophytosis and referred to two mycology referral laboratories in the north of Iran were included in the study. Identification of all dermatophyte isolates was confirmed by RFLP of rDNA internal transcribed spacer (ITS) regions. Antifungal susceptibility testing against five common antifungals using the CLSI-M38-A3 protocol was performed. The TMTISG isolates resistant to TRB, were further analyzed to determine the possible mutations in the SQLE gene. Totally, 647 cases (33%) were positive for dermatophytosis of which 280 cases (43.3%) were identified as members of TMTISG. These were more frequently isolated from tinea corporis 131 (44.56%) and tinea cruris 116 (39.46%). Of 280 TMTISG isolates, 40 (14.3%) were resistant to TRB (MIC ≥ 4 µg/mL), all found to be T. indotineae in ITS sequencing. In SQLE sequencing 34 (85%) of TRB-resistant isolates had coincident mutations of Phe397Leu and Ala448Thr whereas four and two isolates had single mutations of Phe397Leu and Leu393Ser, respectively. Overall, the resistance of Iranian TMTISG isolates to TRB greatly occurred by a mutation of Phe397Leu in the SQLE gene as alone or in combination with Ala448Thr. Nevertheless, for the occurrence of in vitro resistance, only the presence of Phe397Leu mutation seems to be decisive.

Antifungal activity of aminopyrrolnitrin against Trichophyton verrucosum in a guinea pig model of dermatophytosis.

BACKGROUND: Dermatophytosis is a common and major public health concern worldwide. Despite the increasing availability of antifungal drugs, relapses and untreated cases of dermatophyte infections are reported. Therefore, novel antifungal agents are required. Aminopyrrolnitrin (APRN) shows promise for dermatophytosis treatment because of its antifungal activity. OBJECTIVES: This study aimed to assess the antifungal properties of APRN against Trichophyton verrucosum (T. verrucosum), in both laboratory settings and a guinea pig model. METHODS: The minimum inhibitory concentrations (MICs) of APRN and enilconazole against T. verrucosum were determined according to the CLSI M38 method. The skins of 16 male guinea pigs were infected with 1.0 × 108 conidia of T. verrucosum and the animals were grouped into sets of four: negative control group (NC) received normal saline; positive control group (PC) received 2 µg/mL of enilconazole; and APRN4 and APRN8 received 4 and 8 µg/mL of APRN, respectively. Clinical, mycological and histological efficacies were measured after 10 days. RESULTS: The MIC90 of APRN and enilconazole against T. verrucosum was 4 and 2 µg/mL, respectively. The clinical scores of PC, APRN4, and APRN8 were significantly lower than those of NC. Clinical and mycological efficacies were higher for APRN8, APRN4 and PC. No fungi were observed in the skin tissues of APRN4 and APRN8, while fungi were observed in 50% of the PC. CONCLUSION: APRN showed antifungal activity against T. verrucosum in vitro and in vivo and is a potential candidate for the treatment of dermatophytosis.

Dermatophytosis in domestic cats: Identification, and treatment in an Indian context.

The surge in domestic cat adoption across India, particularly the rising preference for high-pedigree cats, coupled with environmental factors, has resulted in increased incidence of dermatophytosis among feline companions. Despite this growing concern, there is a noticeable scarcity of studies in India delving into the etiological factors contributing to dermatophytosis in cats. This disease is a threat to animal health and carries public health significance, given that cats are recognized reservoir hosts for Microsporum canis, a common dermatophyte affecting humans and animals. This study endeavours to identify the dermatophytes affecting cats and establish a standardized therapeutic regimen while accounting for the local stigma surrounding the regular bathing of cats. The study involved the examination of 82 cats presenting dermatological lesions, when subjected to cultural examination in dermatophyte test medium revealed 36 afflicted with dermatophytes. Isolates were presumptively identified by staining using lactophenol cotton blue, Chicago sky blue 6B, and Calcofluor white stains. Molecular-level identification of the isolates was confirmed through PCR-RFLP, amplifying the Internal Transcribed Spacer Sequence of 16 s rDNA, followed by restriction digestion using the Mva1 enzyme. Among the thirty-six isolates, 29 were identified as M. canis, while the remaining 7 were M. gypseum. The cases were categorized into five groups and treated with Lime Sulphur dip, 4 % chlorhexidine shampoo, a shampoo containing 2 % miconazole and 4 % chlorhexidine, oral itraconazole alone, and a combination of oral itraconazole with lime-Sulphur dip. Statistical analysis revealed that the response was notably swifter with lime Sulphur dip when considering only topical therapy. Moreover, the mycological cure was most expeditious when combining Lime Sulphur dip with oral itraconazole. These findings underscore the pivotal role of topical biocides in feline dermatophytosis treatment, potentially reducing the reliance on specific antifungals and thereby contributing to the mitigation of antimicrobial resistance emergence.

Tinea corporis intrafamilial infection in pets due to Microsporum canis.

Microsporum canis, one of the most widespread dermatophytes worldwide, is a zoonotic microorganism that transmits infection from reservoirs such as cats and dogs to humans. This microorganism is associated with Tinea corporis and other clinical manifestations; however, few studies have used genetic surveillance to determine and characterize the process of zoonotic transmission. In this study, we show a clear example of zoonotic transmission from a cat to an intrafamilial environment, where it caused Tinea corporis by infection with M. canis. Molecular characterization using the b-tubulin gene and Random Amplified Polymorphic DNA analysis made it possible to determine that the six isolates of M. canis obtained in this study belonged to the same genetic variant or clone responsible for reservoir-reservoir or reservoir-human transmission.

Dermatophytosis in cats: A comprehensive study on diagnostic methods and their accuracy.

Background: Dermatophytosis is a contagious fungal infection that affects mainly cats. It poses significant challenges in veterinary medicine due to its zoonotic potential and impact on animal and public health. Rapid and reliable diagnosis is crucial for preventing the spread of the disease, guiding treatment decisions, and monitoring disease control efforts. Although there are several studies on diagnostic methods in feline dermatophytosis, the comparison between them from the same sample lacks data. The absence of a universally accepted gold standard diagnostic method highlights the need for a multifaceted approach to diagnosing feline dermatophytosis. Aim: This study aims to assess the accuracy and efficacy of different diagnostic techniques comprehensively. Methods: For this, 48 samples of cats were analyzed by dermoscopy, direct hair examination, fungal culture using various media (Mycosel, Sabouraud, and Dermatophyte Test Medium), and polymerase chain reaction (PCR). Results: Direct examination and dermoscopy yielded unsatisfactory results. Mycosel and Sabouraud were suboptimal. DTM demonstrated superior selectivity, making it the most reliable among traditional methods. PCR was the top performer, exhibiting singular sensitivity, specificity, and accuracy. Conclusion: The study suggests that PCR may be the preferred choice for diagnosing feline dermatophytosis in clinical practice, especially when rapid and accurate results are essential.

Dermatophytomas in Onychomycosis: A Scoping Review of Prevalence, Diagnosis, and Treatment.

BACKGROUND: Dermatophytoma, also described as a longitudinal streak/spike, is a form of onychomycosis that presents as yellow/white streaks or patches in the subungual space, with dense fungal masses encased in biofilm. This scoping review of the literature was conducted to address a general lack of information about the epidemiology, pathophysiology, and treatment of dermatophytomas in onychomycosis. METHODS: A search was performed in the PubMed and Embase databases for the terms "longitudinal spike" or "dermatophytoma." Outcomes of interest were definition, prevalence, methods used for diagnosis, treatments, and treatment efficacy. Inclusion and exclusion of search results required agreement between two independent reviewers. RESULTS: Of a total of 51 records, 37 were included. Two reports provided the first unique definitions/clinical features of dermatophytomas. Overall, many descriptions were found, but one conclusive definition was lacking. Prevalence data were limited and inconsistent. The most frequently mentioned diagnostic techniques were clinical assessment, potassium hydroxide/microscopy, and fungal culture/mycology. Oral terbinafine and topical efinaconazole 10% were the most frequently mentioned treatments, followed by topical luliconazole 5% and other oral treatments (itraconazole, fluconazole, fosravuconazole). In studies with five or more patients without nail excision, cure rates were highest with efinaconazole 10%, which ranged from 41% to 100% depending on the clinical and/or mycologic assessment evaluated. Other drugs with greater than or equal to 50% cure rates were topical luliconazole 5% (50%), oral fosravuconazole (57%), and oral terbinafine (67%). In studies that combined oral terbinafine treatment with nail excision using surgical or chemical (40% urea) methods, cure rates ranged from 50% to 100%. CONCLUSIONS: There is little published information regarding dermatophytomas in onychomycosis. More clinical research and physician education are needed. Although dermatophytomas have historically been considered difficult to treat, the efficacy data gathered in this scoping review have demonstrated that newer topical treatments are effective, as are oral antifungals in combination with chemical or surgical methods.