RESUMEN
The Trichophyton mentagrophytes complex comprises a group of dermatophyte fungi responsible for various dermatological infections. The increasing drug resistance of this species complex, especially terbinafine resistance of Trichophyton indotineae, is a major concern in dermatologist practice. This study provides a comprehensive analysis of T. mentagrophytes complex strains isolated from patients in Hue City, Vietnam, focusing on their phenotypic and genetic characteristics, antifungal susceptibility profiles, and molecular epidemiology. Keratinophilic fungi from dermatophytosis culture samples were identified morphologically and phenotypically, with species and genotypes confirmed by internal transcribed spacer sequencing and phylogenetic analysis. Antifungal susceptibility testing was carried out to evaluate their susceptibility to itraconazole, voriconazole, and terbinafine. The 24% (n = 27/114) of superficial mycoses were phenotypically attributed to T. mentagrophytes complex isolates. Trichophyton interdigitale, mainly genotype II*, was predominant (44.4%), followed by T. mentagrophytes genotype III* (22.2%), T. indotineae (14.8%), T. tonsurans (11.2%), and T. mentagrophytes (7.4%). While all isolates were susceptible to itraconazole and voriconazole, half of T. indotineae isolates exhibited resistance to terbinafine, linked to the Phe397Leu mutation in the SQLE protein. This study highlighted the presence of terbinafine-resistant T. indotineae isolates in Vietnam, emphasizing the need to investigate dermatophyte drug resistance and implement effective measures in clinical practice.
Species diversity within the Trichophyton mentagrophytes complex isolated from dermatophytosis in Hue City, Vietnam, was observed. Terbinafine-resistant T. indotineae isolates were detected for the first time in Vietnam, emphasizing the importance of implementing antifungal susceptibility testing to effectively manage and prevent the spread of resistant isolates.
Asunto(s)
Antifúngicos , Farmacorresistencia Fúngica , Genotipo , Pruebas de Sensibilidad Microbiana , Filogenia , Terbinafina , Tiña , Humanos , Vietnam , Antifúngicos/farmacología , Terbinafina/farmacología , Tiña/microbiología , Arthrodermataceae/efectos de los fármacos , Arthrodermataceae/genética , Arthrodermataceae/clasificación , Arthrodermataceae/aislamiento & purificación , Masculino , Análisis de Secuencia de ADN , Itraconazol/farmacología , ADN Espaciador Ribosómico/genética , Femenino , Persona de Mediana Edad , ADN de Hongos/genética , Epidemiología Molecular , Adulto , TrichophytonRESUMEN
This study analyzed the prevalence and antifungal susceptibility of superficial fungal infections in 295 cases from 2019 to 2020 at a dermatology clinic. Dermatophytes were the predominant pathogens (69.5%), including Trichophytonrubrum, T. interdigitale, Microsporum canis, et al., followed by Candida spp. (29.5%), including Candidaalbicans, Ca. parapsilosis, and Ca. glabrata. The most common infections were onychomycosis (36.3%), tinea cruris (30.5%), and tinea corporis (18.6%). The distribution of SFI types showed variations based on gender, age, and season. Common antifungal agents, including terbinafine, voriconazole, ciclopiroxamine, amphotericin B, itraconazole, and ketoconazole have exhibited low minimum inhibitory concentrations against dermatophytes, especially terbinafine, which has been potent against superficial fungal infections caused by dermatophytes in the local area. Candida spp. strains were generally susceptible or classified as wild-type to 5-flucytosine and amphotericin B, with 92.0% being wild-type for itraconazole. However, resistance to fluconazole and voriconazole was observed in a small percentage of Ca. albicans and Ca. parapsilosis strains. The emergence of drug-resistant Candida underscores the importance of prudent antifungal use and continuous surveillance.
Our study analyzed 295 cases of superficial fungal infections in Taiyuan, located in Northern China. Dermatophytes and Candida spp. were primary pathogens, with varied susceptibilities to antifungals. Results deepen our understanding, emphasizing prudent drug use and surveillance.
Asunto(s)
Antifúngicos , Arthrodermataceae , Candida , Farmacorresistencia Fúngica , Pruebas de Sensibilidad Microbiana , Centros de Atención Terciaria , Humanos , Antifúngicos/farmacología , China/epidemiología , Centros de Atención Terciaria/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Femenino , Adulto , Arthrodermataceae/efectos de los fármacos , Arthrodermataceae/genética , Arthrodermataceae/clasificación , Arthrodermataceae/aislamiento & purificación , Adolescente , Adulto Joven , Niño , Anciano , Candida/efectos de los fármacos , Candida/clasificación , Candida/aislamiento & purificación , Candida/genética , Preescolar , Dermatomicosis/microbiología , Dermatomicosis/epidemiología , Epidemiología Molecular , Prevalencia , Lactante , Anciano de 80 o más AñosRESUMEN
BACKGROUND: dermatophytoses are a current fungal infection, caused by keratinophilic fungi (dermatophytes) able to invade the nails, hair and skin of humans and animals. AIM: the aim of this study was to establish the epidemiological and mycological profile of dermatophytes isolated in the parasitology-mycology laboratory of the Mohammed VI University Hospital in Oujda. METHODS: this is a 48-month retrospective study from January 2019 to December 2022.The study includes samples taken or sent to our parasitology-mycology laboratory for mycological study. A direct examination and culture were performed on each biological specimen. Species identification was based on macroscopic and microscopic colony criteria. RESULTS: in the present report we reviewed 950 mycological samples. Dermatophytes were isolated in 505 (53.15%) cases. The most common infections were tinea unguium (n=353; 69.90%), followed by tinea corporis (n=123; 5.74%) and tinea capitis (n=29; 5.98%). Trichophyton rubrum was the most frequently incriminated species. CONCLUSION: dermatophytes are the most frequent mycoses in humans. They are generally benign and often develop in a chronic and frequently recurrent pattern. Mycological examination is essential. It confirms the fungal origin and isolates the species responsible, in order to identify the source of contamination and implement an appropriate treatment.
Asunto(s)
Arthrodermataceae , Hospitales Universitarios , Humanos , Estudios Retrospectivos , Arthrodermataceae/aislamiento & purificación , Femenino , Masculino , Adulto , Persona de Mediana Edad , Niño , Adolescente , Adulto Joven , Anciano , Preescolar , Tiña/epidemiología , Tiña/microbiología , Tiña/diagnóstico , Dermatomicosis/epidemiología , Dermatomicosis/microbiología , Dermatomicosis/diagnóstico , Marruecos/epidemiología , Lactante , Micología/métodos , Anciano de 80 o más AñosRESUMEN
Over the past few years, a recalcitrant dermatophytosis has been observed on the Indian subcontinent, including Sri Lanka, which has caused a major public health issue in the region. An emerging species, Trichophyton indotineae, first described as Trichophyton mentagrophytes ITS genotype VIII, is thought to be responsible for this fast-spreading, mostly terbinafine-resistant dermatophytosis. Recalcitrant dermatophytosis is a challenge to dermatologists, and knowing the causative species and antifungal sensitivity in the earlier stage of management would be invaluable. We report a case series of patients with dermatophytosis caused by T. indotineae in Sri Lanka. This is the first detection of this highly terbinafine-resistant strain in Sri Lanka, and existence of this species should be taken seriously by dermatologists and healthcare policymakers for better management of tinea infections and antifungal stewardship in the country.
Asunto(s)
Antifúngicos , Genotipo , Terbinafina , Tiña , Humanos , Tiña/tratamiento farmacológico , Tiña/microbiología , Sri Lanka , Antifúngicos/uso terapéutico , Antifúngicos/farmacología , Masculino , Femenino , Terbinafina/uso terapéutico , Adulto , Persona de Mediana Edad , Farmacorresistencia Fúngica , Trichophyton/genética , Trichophyton/aislamiento & purificación , Trichophyton/efectos de los fármacos , Trichophyton/clasificación , Arthrodermataceae/genética , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/efectos de los fármacos , Arthrodermataceae/clasificaciónRESUMEN
Dermatophyte infections frequently pose diagnostic challenges, especially when occurring alongside ichthyosis, a genetic skin disorder characterized by dry, thickened, scaly skin. This case series outlines three cases where dermatophyte infections overlapped with ichthyosis, emphasizing the complexities in clinical identification and differential diagnosis. Atypical clinical presentations in these cases led to initial misdiagnoses. Ichthyosis, a genetic skin disorder characterized by thickened and scaly skin, creates an environment conducive to dermatophyte settlement, complicating the diagnostic process. The cases highlight the importance of considering fungal infections, even when clinical features deviate from the expected course. A vigilant diagnostic approach, including mycological examinations, is crucial for accurate identification and timely management.
Asunto(s)
Dermatomicosis , Ictiosis , Humanos , Masculino , Ictiosis/microbiología , Ictiosis/complicaciones , Ictiosis/diagnóstico , Dermatomicosis/microbiología , Dermatomicosis/diagnóstico , Femenino , Diagnóstico Diferencial , Adulto , Coinfección/microbiología , Coinfección/diagnóstico , Persona de Mediana Edad , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/clasificación , Antifúngicos/uso terapéuticoRESUMEN
BACKGROUND: Despite changes in the epidemiology of dermatophyte infections, the incidence of fungal infections associated with Trichophyton species still remains high among dogs and cats. The objective of the present study was to isolate and characterize dermatophytes from dogs and cats in Iran. METHOD: From December 2022 to May 2023, skin and hair samples were collected from symptomatic and asymptomatic cats and dogs in Mazandaran, a northern province of Iran. The samples were then inoculated into Mycosel™ Agar. Dermatophyte isolates were identified by sequencing the internal transcribed spacer region. Antifungal susceptibility tests were conducted using the Clinical and Laboratory Standards Institute (CLSI-M38-A3). RESULT: Of the 250 samples collected (from 200 dogs and 50 cats), 20 (from 19 dogs and one cat) (8.0 %) were positive for dermatophyte growth. Based on sequence and phylogenetic analysis, all isolates belonged to T. mentagrophytes II*. Of these positive samples, 14 (70.0 %), 3 (15.0 %), 2 (10.0 %), and 1 (2.0 %) were isolated from asymptomatic stray dogs, symptomatic stray dogs, symptomatic domestic dogs, and symptomatic cats, respectively. Luliconazole and terbinafine displayed potent activity against all T. mentagrophytes isolates, with Minimum inhibitory concentration (MIC) values of 0.016 µg/ml. Miconazole and griseofulvin demonstrated higher MIC (1 and 8 µg/ml). CONCLUSION: The present study indicated that T. mentagrophytes II* asymptomatic carriage is frequent in stray dogs in Iran. The potential risk to public health needs to be evaluated However, T. mentagrophytes genotype VIII, considered as an endemic and emerging human pathogenic clone in several countries, was not detected during the present survey.
Asunto(s)
Antifúngicos , Arthrodermataceae , Enfermedades de los Gatos , Enfermedades de los Perros , Pruebas de Sensibilidad Microbiana , Filogenia , Tiña , Perros/microbiología , Gatos/microbiología , Animales , Irán/epidemiología , Enfermedades de los Perros/microbiología , Enfermedades de los Perros/epidemiología , Enfermedades de los Gatos/microbiología , Enfermedades de los Gatos/epidemiología , Antifúngicos/farmacología , Tiña/microbiología , Tiña/epidemiología , Tiña/veterinaria , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/efectos de los fármacos , Arthrodermataceae/genética , Arthrodermataceae/clasificación , Masculino , Femenino , Cabello/microbiología , Infecciones Asintomáticas/epidemiologíaRESUMEN
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.
Asunto(s)
Arthrodermataceae , Arthrodermataceae/genética , Arthrodermataceae/aislamiento & purificación , Humanos , Tiña/microbiología , Tiña/diagnóstico , Subtilisina/genética , Trichophyton/genética , Trichophyton/aislamiento & purificación , Filogenia , Proteínas Fúngicas/genéticaRESUMEN
Data on the epidemiology of tinea capitis (TC), an infection of the scalp by dermatophytes, are scarce in Cameroon. This study aimed to determine the prevalence of TC among school-children in the Dschang Subdivision, Western Cameroon. A cross-sectional study was carried out in June 2021 in Dschang including pupils aged 5-13. First, a standardized questionnaire was administered to participant for the collection of sociodemographic data. Then, samples were collected and cultured onto Sabouraud-Chloramphenicol-Gentamicin Agar. The etiological agents were identified based on their morphological features and with MALDI-TOF mass spectrometry. A total of 1070 children were clinically examined and 108 (10.1%) children presented with TC lesions. The mean age of the 1070 participants was 8.3 ± 2.6 years (range: 5-13 years); 772 (72.2%) were males. The use of borehole water (OR = 0.01, 95%CI[0.001-0.03]), spring water (OR = 0.2, 95%CI[0.08-0.50]), rainwater (OR = 0.004, 95%CI[0.001-0.016]), and hairdressing salons visits (OR = 0.413, 95%CI[0.196-0.872]) were associated with a decreased TC risk in the multivariate logistic regression analysis. In contrast, sharing bed with siblings (OR = 4.48, 95%CI[2.095-9.60]) was associated with an increased TC risk in children. Among the 32 dermatophytes isolated in culture, Microsporum audouinii was the most frequent (43.8%), followed by Trichophyton rubrum (25.0%) and T. soudanense (25.0%). Microsporum canis and T. violaceum were both rarely isolated. Further studies are warranted to assess the association of TC with domestic water usage that has been highlighted in this study.
Asunto(s)
Tiña del Cuero Cabelludo , Tiña del Cuero Cabelludo/epidemiología , Tiña del Cuero Cabelludo/microbiología , Humanos , Camerún/epidemiología , Niño , Masculino , Femenino , Adolescente , Estudios Transversales , Preescolar , Prevalencia , Encuestas y Cuestionarios , Microsporum/aislamiento & purificación , Factores de Riesgo , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/clasificación , Instituciones Académicas , Trichophyton/aislamiento & purificaciónRESUMEN
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.
Asunto(s)
Antifúngicos , Arthrodermataceae , Microsporum , Tiña , Humanos , Estudios Retrospectivos , Femenino , Masculino , Tiña/microbiología , Tiña/tratamiento farmacológico , Tiña/epidemiología , Tailandia/epidemiología , Adulto , Antifúngicos/uso terapéutico , Persona de Mediana Edad , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/clasificación , Arthrodermataceae/efectos de los fármacos , Adulto Joven , Adolescente , Microsporum/aislamiento & purificación , Niño , Resultado del Tratamiento , Anciano , Dermatosis Facial/microbiología , Dermatosis Facial/tratamiento farmacológico , PreescolarRESUMEN
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.
Asunto(s)
Arthrodermataceae , Tiña , Humanos , Masculino , Femenino , Adolescente , China/epidemiología , Niño , Tiña/microbiología , Tiña/epidemiología , Adulto , Persona de Mediana Edad , Preescolar , Adulto Joven , Lactante , Anciano , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/clasificación , Anciano de 80 o más Años , Dermatosis Facial/microbiología , Dermatosis Facial/epidemiología , Dermatosis Facial/patología , Cara/microbiología , Cara/patología , Encuestas y CuestionariosRESUMEN
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.
Asunto(s)
Antifúngicos , Arthrodermataceae , Farmacorresistencia Fúngica , Pruebas de Sensibilidad Microbiana , Mutación Puntual , Escualeno-Monooxigenasa , Tiña , Humanos , Antifúngicos/farmacología , Irak/epidemiología , Tiña/microbiología , Tiña/epidemiología , Tiña/tratamiento farmacológico , Farmacorresistencia Fúngica/genética , Masculino , Arthrodermataceae/genética , Arthrodermataceae/efectos de los fármacos , Arthrodermataceae/patogenicidad , Arthrodermataceae/aislamiento & purificación , Femenino , Escualeno-Monooxigenasa/genética , Adulto , Filogenia , Terbinafina/farmacología , Terbinafina/uso terapéutico , Persona de Mediana Edad , Adolescente , Adulto Joven , Niño , Proteínas Fúngicas/genética , AncianoRESUMEN
BACKGROUND: Onychomycosis is a chronic nail infection, and dermatophytes, yeasts, and nondermatophytic molds may be the causative agents. This study aimed to determine the etiological agents of onychomycosis by using conventional and molecular methods. METHODS: Between June 2020 and July 2021, 37 patients with a presumptive diagnosis of onychomycosis and mycological evidence (culture and/or EUROArray Dermatomycosis assay) were included in the study. Organisms detected in cultured nail specimens were identified by combined phenotypic characteristics and by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). An EUROarray Dermatomycosis assay was used for molecular detection of fungal pathogens. RESULTS: The EUROArray Dermatomycosis assay was positive for a single fungal target in 23 samples, and 14 samples were positive by culture. The most common pathogen was Trichophyton rubrum in both methods. Coinfection was detected in 14 samples by using molecular methods, and Trichophyton rubrum and Fusarium solani (9 samples) were the most common pathogens detected together. Trichophyton spp., nondermatophyte molds, and Candida spp. were detected in 33 (89.2%), 16 (43.2%), and 6 (16.2%) samples, respectively, when the two methods were evaluated together. CONCLUSIONS: Our results revealed that fungal culture allows the diagnosis of onychomycosis, but it is not as sensitive as the EUROArray Dermatomycosis test, especially in patients receiving antifungal therapy.
Asunto(s)
Arthrodermataceae , Onicomicosis , Humanos , Onicomicosis/microbiología , Onicomicosis/diagnóstico , Femenino , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/genética , Masculino , Turquía/epidemiología , Adulto , Persona de Mediana Edad , Anciano , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Adulto Joven , Adolescente , Trichophyton/aislamiento & purificación , Trichophyton/genética , Técnicas de Diagnóstico Molecular/métodos , Coinfección/microbiología , Coinfección/diagnóstico , Coinfección/epidemiologíaRESUMEN
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.
Asunto(s)
Antifúngicos , Enfermedades de los Gatos , Microsporum , Tiña , Gatos/microbiología , Animales , Enfermedades de los Gatos/microbiología , Enfermedades de los Gatos/tratamiento farmacológico , India/epidemiología , Tiña/veterinaria , Tiña/microbiología , Tiña/tratamiento farmacológico , Tiña/epidemiología , Antifúngicos/uso terapéutico , Microsporum/aislamiento & purificación , Microsporum/genética , Masculino , Femenino , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/genética , Arthrodermataceae/clasificación , Arthrodermataceae/efectos de los fármacos , Itraconazol/uso terapéutico , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , ADN de Hongos/genética , ADN Espaciador Ribosómico/genéticaRESUMEN
Tinea capitis (TC) is still a frequent dermatophytosis in France, both autochthonous and imported. A nationwide retrospective survey was performed and a total of 4395 TC cases were recorded within 36 French mycology laboratories during a 6-year period. TC is a disease that occurs in childhood with 85% of the cases occurring before 10 years old and 94% before the age of 15. Anthropophilic origin was predominant with 779 cases of Trichophyton tonsurans (32.6%), 738 cases of Trichophyton soudanense/T. violaceum (31%), and 445 cases of Microsporum audouinii (19.2%). Of note, T. tonsurans represents more than 80% of the cases in the French West Indies (Martinique and Guadeloupe). By contrast, zoophilic species were less prevalent with mainly M. canis (10.3%) confirming the shift from zoophilic to anthropophilic species observed in many centers during the last decades. During this survey, diagnosis methods were also collected. Most labs had a classical process for the diagnosis: microscopic direct examination associated to cultures on Sabouraud and Sabouraud-cycloheximide media (incubated between 25 ± 5°C for at least 3 weeks) in all laboratories. Identification of the causal dermatophyte was performed by microscopic and macroscopic examination of the cultures in 100% of the labs, with various specific culture media available when fructification was insufficient (mainly malt or potato-dextrose agar, or Borelli medium). New techniques were also implemented with the introduction of MALDI-TOF mass spectrometry identification in more than two third of the labs, and molecular identification available if necessary in half of the labs.
A total of 4395 tinea capitis cases were recorded within 36 French mycology laboratories during a 6-year period. An anthropophilic origin was predominant with 33%, 31%, and 18.8% of cases due to Trichophyton tonsurans, T. soudanense/T. violaceum, and Microsporum audouinii, respectively.
Asunto(s)
Microsporum , Tiña del Cuero Cabelludo , Humanos , Tiña del Cuero Cabelludo/epidemiología , Tiña del Cuero Cabelludo/microbiología , Tiña del Cuero Cabelludo/tratamiento farmacológico , Estudios Retrospectivos , Francia/epidemiología , Niño , Microsporum/aislamiento & purificación , Adolescente , Preescolar , Masculino , Femenino , Arthrodermataceae/aislamiento & purificación , Arthrodermataceae/clasificación , Trichophyton/aislamiento & purificación , Prevalencia , Encuestas y Cuestionarios , Lactante , AdultoRESUMEN
We describe a novel assay and artificial intelligence-driven histopathologic approach identifying dermatophytes in human skin tissue sections (ie, B-DNA dermatophyte assay) and demonstrate, for the first time, the presence of dermatophytes in tissue using immunohistochemistry to detect canonical right-handed double-stranded (ds) B-DNA. Immunohistochemistry was performed using anti-ds-B-DNA monoclonal antibodies with formalin-fixed paraffin-embedded tissues to determine the presence of dermatophytes. The B-DNA assay resulted in a more accurate identification of dermatophytes, nuclear morphology, dimensions, and gene expression of dermatophytes (ie, optical density values) than periodic acid-Schiff (PAS), Grocott methenamine silver (GMS), or hematoxylin and eosin (H&E) stains. The novel assay guided by artificial intelligence allowed for efficient identification of different types of dermatophytes (eg, hyphae, microconidia, macroconidia, and arthroconidia). Using the B-DNA dermatophyte assay as a clinical tool for diagnosing dermatophytes is an alternative to PAS, GMS, and H&E as a fast and inexpensive way to accurately detect dermatophytosis and reduce the number of false negatives. Our assay resulted in superior identification, sensitivity, life cycle stages, and morphology compared to H&E, PAS, and GMS stains. This method detects a specific structural marker (ie, ds-B-DNA), which can assist with diagnosis of dermatophytes. It represents a significant advantage over methods currently in use.
Asunto(s)
Arthrodermataceae , Inteligencia Artificial , ADN de Hongos , Humanos , Arthrodermataceae/aislamiento & purificación , ADN de Hongos/análisis , Inmunohistoquímica , Tiña/diagnóstico , Tiña/microbiología , Piel/microbiología , Piel/patología , Sensibilidad y Especificidad , Dermatomicosis/diagnóstico , Dermatomicosis/microbiologíaRESUMEN
Dermatophyte infections (a.k.a. ringworm, tinea) affect an estimated 20%-25% of the world's population. In North America, most dermatophytoses are caused by Trichophyton rubrum or Trichophyton mentagrophytes species complexes. Severe and antifungal-resistant dermatophytoses are a growing global public health problem. A new species of the T. mentagrophytes species complex, Trichophyton indotineae, has recently emerged and is notable for the severe infections it causes, its propensity for antifungal resistance, and its global spread. In this issue of the Journal of Clinical Microbiology, C. F. Cañete-Gibas, J. Mele, H. P. Patterson, et al. (J Clin Microbiol 61:e00562-23, 2023, https://doi.org/10.1128/JCM.00562-23) summarize the results of speciation and AFST performed on North American dermatophyte isolates received at a fungal diagnostic reference laboratory. Within their collection, 18.6% of isolates were resistant to terbinafine (a first-line oral antifungal for dermatophytoses), and similar proportions of T. rubrum and T. indotineae demonstrated terbinafine resistance. The authors also found that T. indotineae has been present in North America since at least 2017. These findings highlight the importance of increased surveillance efforts to monitor trends in severe and antifungal-resistant dermatophytoses and the need for antifungal stewardship efforts, the success of which is contingent upon improving laboratory capacity for dermatophyte speciation and AFST.
Asunto(s)
Arthrodermataceae , Tiña , Humanos , Terbinafina , Antifúngicos/farmacología , Arthrodermataceae/aislamiento & purificación , Tiña/tratamiento farmacológico , Tiña/epidemiología , Pruebas de Sensibilidad Microbiana , Trichophyton/clasificación , Farmacorresistencia Fúngica/efectos de los fármacosRESUMEN
Recalcitrant dermatophytosis has had an alarming rise in India with concomitant decreased effectiveness of conventional antifungal agents. This has prompted the use of second-line agents for treatment. In this retrospective study, we aimed to analyze the response rate, efficacy, relapse rate, and side effects of oral ketoconazole (KZ) in the treatment of recalcitrant tinea corporis and cruris. Institutional records were reviewed for patients presenting with tinea cruris or corporis who had failed treatment with conventional antifungal drugs and treated with oral KZ. Potassium hydroxide (KOH) findings, culture reports, and response to treatment was noted based on the percentage improvement in lesions and reduction in itching compared with baseline. Fourty-three patients (mean age 31.3 years) with tinea corporis/cruris who had taken prior treatment with antifungals were recruited in the study. KOH mount and culture were positive in 76.7% patients. Trichophyton mentagrophytes was the commonest species, isolated in 62.8% of patients. Ketoconazole showed the lowest minimum inhibitory concentration on antifungal susceptibility tests with various antifungals. With a dose of 400 mg daily, 67.4% of patients were cured of disease with mean duration of 9.4 weeks. Patients having less than 40% clearance at 2 weeks had a 68.9% less probability of getting cured of disease. Of the 29 patients cured, 37.9% relapsed because of various predisposing factors. Two patients developed increase in liver enzymes on treatment. Our analysis suggests that KZ can be used as alternative drug in cases with failure to conventional antifungal drugs. Though there are relapses, these can be partially explained by various predisposing factors that support fungal survival and transmission.