Genome-wide association study of dermatophytosis in the UK Biobank cohort.

BACKGROUND: Analyses of the hereditary propensity to dermatophytosis have revealed several proven genetic relationships. They include CARD9 deficiency, HLA-DR4 and HLA-DR8 type and genes encoding interleukin-22, defensin 2 and 4, and genetic defects in dectin-1, which increased the prevalence of dermatophytosis in families and were involved in the inheritance of susceptibility in their members. METHODS: To further investigate the genetic basis of dermatophytosis, we performed a genome-wide association study (GWAS) of the UK Biobank cohort. To identify cases of dermatophytosis, we used ICD10 code B35, which covers Tinea barbae, Tinea capitis, Tinea unguium, Tinea manuum, Tinea pedis, Tinea corporis, Tinea imbricata, Tinea cruris, other dermatophytoses and dermatophytosis, unspecified. Data processing was performed on Minerva, a Linux mainframe with Centos 7.6, at the Icahn School of Medicine at Mount Sinai. We used PLINK, a whole-genome association analysis toolset, to analyse the UKB chromosome files and the UK Biobank Data Parser (ukbb parser), a python-based package that allows easy interfacing with the large UK Biobank dataset. We used LocusZoom for the Manhattan and q-q plots. Other statistical analyses were done with R and SPSS 25. RESULTS: Genome-wide association study (GWAS) and meta-analysis association statistics highlighted one susceptibility locus, Tubulointerstitial Nephritis Antigen (TINAG), with genome-wide significance for dermatophytosis. The top SNP was rs16885197, a missense variant within TINAG, position chr6:54308557, alleles A > G, minor allele frequency (MAF) 0.014. Multivariate logistic regression indicated that the minor G allele increased odds ratio of dermatophytosis by 7.8. Carrying two G alleles raised dermatophytosis odds ratio by a factor of 14. CONCLUSION: More research into genetic and other predisposing factors for dermatophytosis is critical because of the implications for prophylaxis and therapy. It might be possible to prevent infection and recurrence by identifying people who are vulnerable to chronic dermatophytosis. Identifying high-risk families would enable their members to be educated about the dangers of fungal diseases. New therapeutic techniques to target altered hormonal and immune response pathways might be created. TINAG is a prospective target that should be investigated, based on the findings of this article.

Landscape of keratinocytes transcriptome alterations in response to Trichophyton mentagrophytes infection.

Dermatophytosis is an intractable superficial fungal infection of keratinized structures, with approximately 20% incidence in humans. Alterations of keratinocytes in the pathogenesis of dermatophytosis at the transcriptome level remain unclear. To understand and characterize such responses, keratinocytes were infected with Trichophyton mentagrophytes. After infection with 1 × 105 conidia/mL T. mentagrophytes for 24 h, the adherence of fungal hyphae to keratinocytes and the damage caused to cell morphology and structure were observed by light microscopy and transmission electron microscopy, respectively. Levels of pro-inflammatory cytokines IL-1α, IL-1ß, TNFα, and IL-8 significantly increased after infection. RNA-seq and bioinformatic analyses revealed that 766 genes were significantly whereas 2207 genes were repressed in the T. mentagrophyte-infected cells. Some of the differentially expressed genes (DEGs) were related to inflammation, immune responses, wound healing, metabolism, and oxidative stress. GO and KEGG pathway enrichment analyses revealed that DEGs and pathways involved in inflammatory response, immune response, and pathogen-induced dysfunction were significantly enriched in the infected cells. Furthermore, gene set enrichment analysis revealed that higher expression gene sets were mainly involved in immune responses, whereas lower expression gene sets were related to cell component organization or biogenesis and transporter activity. Furthermore, protein-protein interaction network and function analyses revealed that JUN, TP53, FOS, MYC, and HSP90AA1 play a key role in immune responses. Overall, our study systematically uncovered the transcriptome-level response of keratinocytes to T. mentagrophyte and provided insights into dermatophytosis treatment.

An ancient haplotype containing antimicrobial peptide gene variants is associated with severe fungal skin disease in Persian cats.

Dermatophytosis, also known as ringworm, is a contagious fungal skin disease affecting humans and animals worldwide. Persian cats exhibit severe forms of the disease more commonly than other breeds of cat, including other long-haired breeds. Certain types of severe dermatophytosis in humans are reportedly caused by monogenic inborn errors of immunity. The goal of this study was to identify genetic variants in Persian cats contributing to the phenotype of severe dermatophytosis. Whole-genome sequencing of case and control Persian cats followed by a genome-wide association study identified a highly divergent, disease-associated haplotype on chromosome F1 containing the S100 family of genes. S100 calcium binding protein A9 (S100A9), which encodes a subunit of the antimicrobial heterodimer known as calprotectin, contained 13 nonsynonymous variants between cases and controls. Evolutionary analysis of S100A9 haplotypes comparing cases, controls, and wild felids suggested the divergent disease-associated haplotype was likely introgressed into the domestic cat lineage and maintained via balancing selection. We demonstrated marked upregulation of calprotectin expression in the feline epidermis during dermatophytosis, suggesting involvement in disease pathogenesis. Given this divergent allele has been maintained in domestic cat and wildcat populations, this haplotype may have beneficial effects against other pathogens. The pathogen specificity of this altered protein should be investigated before attempting to reduce the allele frequency in the Persian cat breed. Further work is needed to clarify if severe Persian dermatophytosis is a monogenic disease or if hidden disease-susceptibility loci remain to be discovered. Consideration should be given to engineering antimicrobial peptides such as calprotectin for topical treatment of dermatophytosis in humans and animals.

Genetic Predisposition and its Heredity in the Context of Increased Prevalence of Dermatophytoses.

Dermatophytosis is a widespread disease with high prevalence and a substantial economic burden associated with costs of treatment. The pattern of this infectious disease covers a wide spectrum from exposed individuals without symptoms to those with acutely inflammatory or non-inflammatory, chronic to invasive, and life-threatening symptoms. Moreover, the prevalence of cutaneous fungal infections is not as high as might be expected. This curious disparity in the dermatophyte infection patterns may suggest that there are individual factors that predispose to infection, with genetics as an increasingly well-known determinant. In this review, we describe recent findings about the genetic predisposition to dermatophyte infections, with focus on inheritance in families with a high frequency of dermatophyte infections and specific host-pathogen interactions. The results of studies indicating a hereditary predisposition to dermatophytoses have been challenged by many skeptics suggesting that the varied degree of pathogenicity and the ecological diversity of this group of fungi are more important in increasing sensitivity. Nonetheless, a retrospective analysis of the hereditary propensity to dermatophytoses revealed at least several proven genetic relationships such as races, CARD9 deficiency, HLA-DR4 and HLA-DR8 type and responsible genes encoding interleukin-22, ß-defensin 2 and 4 as well as genetic defects in dectin-1, which increased the prevalence of the disease in families and were involved in the inheritance of the proneness in their members. In future, the Human Genome Diversity Project can contribute to elucidation of the genetic predisposition to dermatophytoses and provide more information.

Gene expression profiling of protease and non-protease genes in Trichophyton mentagrophytes isolates from dermatophytosis patients by qRT-PCR analysis.

Trichophyton mentagrophytes secretes Metallocarboxypeptidase A and B of the M14 family as endoproteases and exoprotease. T. mentagrophytes produce Metalloprotease 3 and 4 which degrades the protein into the short peptides and amino acids. To understand the host fungal relationship and identification of such genes expressed during infection is utmost important. T. mentagrophytes encodes some proteins which are associated with the glyoxylate cycle. The glyoxylate cycle enzymes have been involving in virulence of dermatophytes and their up-regulation during dermatophytes growth on keratin. On comparing the expression level of virulence protease and non-protease genes, we observed, among exoprotease protease genes, Metallocarboxypeptidase B was strongly up regulated (134.6 fold high) followed by Metallocarboxypeptidase A (115.6 fold high) and Di-peptidyl-peptidases V (10.1 fold high), in dermatophytic patients as compared to ATCC strain. Furthermore, among endoprotease, Metalloprotease 4 was strongly up regulated (131.6 fold high) followed by Metalloprotease 3 (16.7 fold high), in clinical strains as compared to T. mentagrophytes ATCC strain. While among non-protease genes, Citrate Synthase was highly expressed (118 fold high), followed by Isocitrate Lyase (101.6 fold high) and Malate Synthase (52.9 fold high). All the studied virulence genes were considered the best suitable ones by geNorm, Best keeper, Norm Finder and Ref finder.

Molecular identification of isolates of the Trichophyton mentagrophytes complex.

Background: The Trichophyton mentagrophytes complex is the second most common causal agent of dermatophytosis. It comprises five species-T. mentagrophytes, T. interdigitale, T. erinacei, T quinckeanum, and T. benhamie, as well as nine different genotypes of T. mentagrophytes / T. interdigitale-which are morphologically similar; however, their susceptibility to antifungal agents may differ. For targeted therapy and better prognosis, it is important to identify these species at a molecular level. However, since many hospitals lack molecular methods, the actual aetiology of dermatophytosis caused by this complex remains unknown. Objective: To characterize 55 anthropophilic isolates of the T. mentagrophytes complex recovered from a dermatological centre in Yucatán, Mexico. Material and methods: Fifty-five isolates of the T. mentagrophytes complex were obtained from patients with tinea capitis, tinea pedis, tinea corporis, tinea barbae, and tinea unguium. They were characterized by their colonial and microscopic morphology on Sabouraud dextrose agar (SDA) and through the sequencing of a fragment from the region ITS1-5.8S-ITS2. Results: All colonies grown on SDA were white. Forty-six isolates formed colonies with a powdery texture, while nine isolates formed colonies with a velvety texture. The micromorphological features were typical of the T. mentagrophytes complex. The molecular analysis revealed that 55 isolates were microorganisms that belonged to the T. mentagrophytes complex, that 46 formed powdery colonies representing T. mentagrophytes, and that the other nine isolates that formed velvety colonies represented T. interdigitale. The latter nine isolates were obtained from patients with tinea pedis, tinea corporis, and tinea unguium. Conclusions: The colony morphology on SDA led to the identification of 46 isolates as T. mentagrophytes and nine isolates as T. interdigitale. At a molecular level, the species identified by their morphology were identified only as T. mentagrophytes complex.

Rapid detection of terbinafine resistance in Trichophyton species by Amplified refractory mutation system-polymerase chain reaction.

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 397th 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.

MiR-155, a potential serum marker of extramammary Paget's disease.

BACKGROUND: Extramammary Paget's disease (EMPD), a rare skin malignancy with non-specific manifestations, is often misdiagnosed as eczema of scrotum or tinea cruris. Although the diagnosis of EMPD could be confirmed by biopsy, it can be delayed as patients are reluctant to receive invasive operations. Herein, we investigated the serum miRNA expressions of EMPD patients and compared to that of the eczema of scrotum or tinea cruris patients as well as health volunteers for potential diagnostic markers for EMPD. METHODS: Altogether 45 subjects including 16 patients diagnosed with EMPD, 12 patients diagnosed with eczema of scrotum or tinea cruris and 17 healthy volunteers were enrolled in this study. Serum from all of subjects were collected to identify miRNAs (by miRNA array global normalization, RT-PCR validation, and receiver operating characteristic curve analysis) that could be potential diagnostic markers for EMPD. RESULTS: The miRNA array analyses revealed that the expressions of 37 miRNAs from the EMPD patients were different (change ≥4-fold) from health volunteers. Among these miRNAs, the expression of miR-155 was significantly increased (p < 0.01) in the EMPD patients as compared with that of the health volunteers and the eczema of scrotum or the tinea cruris patients (no difference between these two control groups). In addition, receiver operating characteristic (ROC) curve analysis showed that diagnostic capacities (defined as the area under curve of ROC) of miR-155 are 0.85 (as compared with health volunteers group) and 0.81 (as compared with the eczema of scrotum or the tinea cruris patients group), respectively. CONCLUSION: The serum miRNA expression of gene miR-155 in the EMPD patients was differentiated from that of other subjects warranting further validation of miR-155 as a diagnostic marker of EMPD.

Exoproteome Analysis of Human Pathogenic Dermatophyte Species and Identification of Immunoreactive Proteins.

PURPOSE: Increasing incidence of onychomycosis and tinea pedis in humans of industrialized countries together with deep tissue infections are a therapeutic challenge in clinical mycology. For a better understanding of the pathology and immunology of infection, the authors analyze the exoproteomes of three reference strains of the most common clinical dermatophyte species (Trichophyton rubrum, Trichophyton interdigitale, Arthroderma benhamiae) and of Trichophyton strains isolated from affected patients. EXPERIMENTAL DESIGN: Extracellular proteins of those in vitro grown strains are separated via 2D High Performance Electrophoresis and identified by mass spectrometry to find proteins with provoked host immune reactivity. RESULTS: More than 80 secreted proteins including virulence factors such as peptidases and other hydrolases are identified. By Western blotting with respective patient sera, up to 31 proteins with significant antigen-antibody reactions are detected in comparison with control sera, for example, peptidases as well as several oxidoreductases. One protein, beta-glucosidase F2SZI9 seems to be a commonly processed antigen in all Trichophyton infections. CONCLUSIONS AND CLINICAL RELEVANCE: These first global exoproteome data of three dermatophyte species can be a stepping stone on the way to further study the molecular mechanisms of Trichophyton pathogenicity-associated traits. Possible candidates for potential new diagnostic methods or vaccination have to be validated in further investigations.

Landscape of long non-coding RNAs in Trichophyton mentagrophytes-induced rabbit dermatophytosis lesional skin and normal skin.

Emerging evidences suggest that long non-coding RNAs (lncRNAs) play important role in disease development. However, the role of rabbit lncRNAs in the pathogenesis of dermatophytosis remains elusive. The present study aimed to study and characterize lncRNA transcriptome in 8 T. mentagrophytes-induced female rabbit dermatophytosis lesional (TM) and 4 normal saline-infected (NS) skin biopsies using RNAseq. We identified 5883 lncRNAs in 12 strand-specific RNA-seq libraries and found 64 differentially expressed lncRNAs (q < 0.05) in TM relative to NS. As in other mammalian counterparts, rabbit lncRNAs were distributed in all chromosomes except the Y chromosome and were generally smaller in size and fewer in exon numbers compared to protein coding genes. Next, co-expression analysis revealed that 107 pairs between 32 DE lncRNAs and 96 protein coding genes showed a highly correlated expression (|r| > 0.8). Moreover, miRPara analysis of the lncRNAs revealed 173 lncRNAs with precursor sequences for 9561 probable novel miRNAs. Finally, q-PCR results validated the RNA-seq results with eight randomly selected lncRNAs. To the best of our knowledge, this is the first report on rabbit lncRNAs, and our results highlighted the potential role of lncRNAs in the pathogenesis of dermatophytosis.

Dermatophytic disease with deficit in CARD9: A new case with a brain impairment.

INTRODUCTION: Dermatophytic disease individualized by Hadida and Schousboe in 1959 is a rare form of chronic dermatophyte infection; characterized by subcutaneous and visceral invasion and a therapeutic failure. We report a case of dermatophytic disease with brain abscess in an Algerian patient. OBSERVATIONS: The patient was 47-year-old, she was born parents first cousins. She had since the age of 10 years scaly scalp lesions that became secondarily papular and nodular. At the age of 17 years, the patient had a generalized skin involvement with multiple nodular lesions, diffuse disease of the nails (plurionyxis), poly lymphadenopathies affecting the cervical, axillary and inguinal areas. Mycological tests identified Trichophyton rubrum. Histopathological examinations showed caseiform necrosis with epithelioid and giant cells. PAS staining showed hyphae in necrosis. The rest of the blood and urine tests were normal. Sequencing CARD9 allowed to highlight a homozygous mutation Q289X. The evolution was marked by an appearance at the age of 47 of a right cerebral abscess fronto-temporo-parietal, cortico-subcortical detected by MRI. The patient was given itraconazole 200mg/day with good evolution after three months of decline. DISCUSSION: Dermatophytic disease is very rare. Fifty cases have been published, mostly from North Africa, a strong endogamy region. Signs and symptoms almost always start with a scalp ringworm with almost constant occurrence of complications: in our patient a cerebral localization with a good evolution with itraconazole. Immunologically it is characterized by an autosomal recessive deficiency CARD9. This observation is notable for the onset of the disease at an early age, the dermatophyte T. rubrum and the favourable outcome of the brain lesion with itraconazole. CONCLUSION: Dermatophytic disease is rare, often severe. Our case is original because of the occurrence of a cerebral localization with good response to itraconazole and its mechanism of action deserves to be elucidated.

Molecular strain typing of Trichophyton mentagrophytes (T. mentagrophytes var. interdigitale) using non-transcribed spacer region as a molecular marker.

Background & objectives: : Dermatophytes are keratinophilic fungi that infect keratinized tissues of human and animal origin. Trichophyton mentagrophytes is considered to be a species complex composed of several strains, which include both anthropophiles and zoophiles. Accurate discrimination is critical for comprehensive understanding of the clinical and epidemiological implications of the genetic heterogeneity of this complex. Molecular strain typing renders an effective way to discriminate each strain. The objective of the study was to characterize T. mentagrophytes clinical isolates to sub-species level using molecular techniques and non-transcribed spacer (NTS) region as marker. Methods: Sixty four T. mentagrophytes clinical isolates were identified by phenotypic methods. These were subjected to polymerase chain reaction targeting three sub-repeat elements (SREs), TmiS0, TmiS1 and TmiS2 of the NTS region. Sequence analysis of internal transcribed spacer (ITS) region of different types was also done. Results: Strain-specific polymorphism was observed in all three loci. Totally, 13 different PCR types were obtained on combining all the three SREs loci. No variation was observed in the ITS region. Interpretation & conclusions: The study described the usefulness of molecular strain typing technique for the discrimination of the T. mentagrophytes isolates. This will help for the future explorations into the epidemiology of T. mentagrophytes and its complex.

Genetic Predictors of Susceptibility to Dermatophytoses.

Countless observational studies conducted over the last century reveal that dermatophytes infect humans of every age, race, gender, and socioeconomic status with strikingly high rates. The curious disparity in dermatophyte infection patterns observed within and between populations has led countless investigators to explore whether genetics underlie a susceptibility to, or confer protection against, dermatophyte infections. This paper examines the data that offer a link between genetics and dermatophytoses and discusses the underlying mechanisms that support these observations.

Characterization of clinically important dermatophytes in North of Iran using PCR-RFLP on ITS region.

OBJECTIVE: Dermatophytosis is considered as one of the major public health problems in the world. Accurate identification of the dermatophytes species is important for recognition of the environment and animal sources of infection. In this survey, 1500 clinical specimens taken from outpatients suspected of dermatophytosis and they were examined by direct microscopy and culture. MATERIALS AND METHODS: In total, three hundred and twelve dermatophytes were isolates recovered in culture, they were identified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method based on the ribosomal DNA internal transcribed spacer (ITS) regions. RESULTS: Tinea pedis was the most common clinical form (32.1%) followed by tinea cruris (24.4%), tinea manuum (16.4%), tinea unguium (8.3%), tinea corporis (7.3%), tinea faciei (6.4%), and tinea capitis (5.1%). Trichophyton interdigitale was the most frequent isolate (38.2%), followed by Trichophyton rubrum (29.8%), Epidermophyton floccosum (16.6%), Trichophyton tonsurans (14.8%) and Microsporum canis (0.6%). The frequency of dermatophytosis was higher in males than in females and in the age-group of 21-30 years. CONCLUSION: Our finding indicated that the incidence of dermatophytosis caused by anthropophilic dermatophytes in Mazandaran province is increasing. Also, this study provides valuable data for the prevention and control of dermatophytosis in the southern coast of the Caspian Sea.

Exhaustive Genome-Wide Search for SNP-SNP Interactions Across 10 Human Diseases.

The identification of statistical SNP-SNP interactions may help explain the genetic etiology of many human diseases, but exhaustive genome-wide searches for these interactions have been difficult, due to a lack of power in most datasets. We aimed to use data from the Resource for Genetic Epidemiology Research on Adult Health and Aging (GERA) study to search for SNP-SNP interactions associated with 10 common diseases. FastEpistasis and BOOST were used to evaluate all pairwise interactions among approximately N = 300,000 single nucleotide polymorphisms (SNPs) with minor allele frequency (MAF) ≥ 0.15, for the dichotomous outcomes of allergic rhinitis, asthma, cardiac disease, depression, dermatophytosis, type 2 diabetes, dyslipidemia, hemorrhoids, hypertensive disease, and osteoarthritis. A total of N = 45,171 subjects were included after quality control steps were applied. These data were divided into discovery and replication subsets; the discovery subset had > 80% power, under selected models, to detect genome-wide significant interactions (P < 10(-12)). Interactions were also evaluated for enrichment in particular SNP features, including functionality, prior disease relevancy, and marginal effects. No interaction in any disease was significant in both the discovery and replication subsets. Enrichment analysis suggested that, for some outcomes, interactions involving SNPs with marginal effects were more likely to be nominally replicated, compared to interactions without marginal effects. If SNP-SNP interactions play a role in the etiology of the studied conditions, they likely have weak effect sizes, involve lower-frequency variants, and/or involve complex models of interaction that are not captured well by the methods that were utilized.