Project description:Purpose: The dermatophyte Trichophyton rubrum is an anthropophilic filamentous fungus that infects keratinized tissues and is the most common etiologic agent isolated in cases of human dermatophytoses. To better understand the molecular effects of stress responses and fungal adaptability, we evaluated the effects of acriflavine, a cytoxic drug, on T. rubrum transcriptome in a time-course assay using high-throughput RNA-seq technology. Results: RNA-seq generated approximately 200 million short reads that were mapped to the Broad Institute’s Dermatophyte Comparative Database before differential gene expression analysis. A subset of 490 genes modulated in response to stress caused T. rubrum exposure to acriflavine were identified. These genes are involved in various cellular processes such as oxidation-reduction reactions, transmembrane transport, metal ion binding, and pathogenicity. The genes involved in pathogenicity were down-regulated, suggesting that this drug interferes with virulence factors that allow the establishment and maintenance of host infection. Conclusion: The results obtained in this large-scale analysis provide insights into the molecular events underlying the stress responses of T. rubrum Acriflavine.
Project description:A cDNA microarray was constructed from the expressed sequence tags (ESTs) of different developmental stages, and comparative genome hybridization based on microarray procedures were carried out. Dermatophyte species are classified into three genera: Epidermophyton, Microsporum, and Trichophyton. To determine the relationship between these three groups comparative genome hybridization were used in our experiment. Trichophyton rubrum genmic DNA was reference DNA and labelled by Cy3 while the other dermatophytes genomic DNA were test DNA and labelled by CY5. Test and reference DNA were co-hybridized with the T. rubrum cDNA microarray and the numbers of genes shared between each species and T. rubrum were determined. Keywords: Comparative Genomic Hybridization We used a Trichophyton rubrum cDNA microarray prepared in our lab through comparative genome hybridization of genomic DNA of 21 dermatophyte strains (belonging to 20 species) to elucidate the taxonomy and evolution profiles of 20 dermatophyte species. The numbers of genes shared between each species and T. rubrum were determined. Each strain DNA hybridized for 3 times. The slides were separated into three groups base on different datasets.
Project description:Dermatophytes are highly specialized filamentous fungi which cause the majority of superficial mycoses in humans and animals. The high secreted proteolytic activity of these microorganisms during growth on proteins is assumed to be linked with their particular ability to exclusively infect keratinized host structures such as skin stratum corneum, hair and nails. Individual secreted dermatophyte proteases were recently described and linked with the in vitro digestion of keratin. However, the overall adaptation and transcriptional response of dermatophytes during protein degradation is largely unknown. To address this question, we constructed a cDNA microarray for the human pathogenic dermatophyte Trichophyton rubrum, which is based on transcripts of the fungus grown on proteins. Gene expression profiling during growth of T. rubrum on soy and keratin displayed the activation of a large set of genes encoding endo- and exoproteases. In addition, other specifically induced factors with potential implication in protein utilization were identified, including heat shock proteins, transporters, metabolic enzymes, transcription factors and hypothetical proteins with unknown function. This broad-scale transcriptional analysis of dermatophytes during growth on proteins reveals new putative pathogenicity related host adaptation mechanism of these human pathogenic fungi. Keywords: Two-condition experiment, strong proteolytic activity in the supernatant versus no proteolytic activity
Project description:Each year, millions of people worldwide are affected by superficial mycoses, which are frequently caused by dermatophytes having affinity to the scalp, nails, hair and the stratum corneum of the skin. The changing reservoirs of zoophilic dermatophytes, the numerous reports of animal carrier status, and the increasing number of pets make the diagnosis difficult, which is usually impossible based only on medical history. Herein we present a case report of tinea corporis caused by Trichophyton equinum in siblings who had no contact with horses. The routine laboratory diagnostic procedures for identification of isolates were based on phenotypic and genotypic characteristics, especially molecular techniques using rDNA internal transcribed spacer sequences. The results showed that both techniques proved to be insufficiently discriminatory to differentiate two closely related species, i.e. Trichophyton equinum and Trichophyton tonsurans. Introduction of a TEF1 sequence analysis to the diagnostic procedures revealed consistent differences between these two species and facilitated unambiguous identification. Interestingly, dogs that could leave the homestead freely were the source of the infection in children. In conclusion, Trichophyton equinum was considered in the past as a strict zoophilic dermatophyte associated with horses and rarely transmitted to humans. This study revealed that this species can have other reservoirs and live in the fur of asymptomatic animals.
Project description:Dermatophytes are highly specialized filamentous fungi which cause the majority of superficial mycoses in humans and animals. The high secreted proteolytic activity of these microorganisms during growth on proteins is assumed to be linked with their particular ability to exclusively infect keratinized host structures such as skin stratum corneum, hair and nails. Individual secreted dermatophyte proteases were recently described and linked with the in vitro digestion of keratin. However, the overall adaptation and transcriptional response of dermatophytes during protein degradation is largely unknown. To address this question, we constructed a cDNA microarray for the human pathogenic dermatophyte Trichophyton rubrum, which is based on transcripts of the fungus grown on proteins. Gene expression profiling during growth of T. rubrum on soy and keratin displayed the activation of a large set of genes encoding endo- and exoproteases. In addition, other specifically induced factors with potential implication in protein utilization were identified, including heat shock proteins, transporters, metabolic enzymes, transcription factors and hypothetical proteins with unknown function. This broad-scale transcriptional analysis of dermatophytes during growth on proteins reveals new putative pathogenicity related host adaptation mechanism of these human pathogenic fungi. Keywords: Two-condition experiment, strong proteolytic activity in the supernatant versus no proteolytic activity Three independently prepared T. rubrum replicates grown in each of the three media, Sabouraud, soy and keratin-soy medium (designated SabA/B/C, soyA/B/C and keratin-soyA/B/C) were used. Pairwise transcriptional comparisons, i.e. soy versus Sabouraud, keratin-soy versus Sabouraud and keratin-soy versus soy were done. The total number of slides in this study was 9.