Kazushi Anzawa

Successful mating of Trichophyton rubrum with Arthroderma simii

Crossing of Trichophyton rubrum with Arthroderma simii yielded many ascomata around the fluffy T. rubrum colonies. One of the 35 supposed ascospores isolated from matured ascoma was shown to be a hybrid of the two species. Hybrids were observed within the genotypes of four different genes, i.e., rRNA, actin, DNA topoisomerase II and cytochrome b. These results strongly suggest that T. rubrum is not an asexual or clonal species.

Case of dermatophyte abscess caused by Trichophyton rubrum: a case report and review of the literature

A 54‐year‐old Japanese man without apparent immunosuppression presented with nodules with purulent drainage on the right lower leg. He had ringworm of the right leg and tinea unguium. A biopsy specimen of the nodule showed intradermal abscesses with fungal elements, and Trichophyton rubrum was cultured from both the pus and the biopsy specimen. Treatment with oral terbinafine resolved the nodules. Dermatophyte abscess is a rare, deep and invasive dermatophytosis, which is often associated with immunocompromised conditions. We provide a review of the literature including Japanese cases.

Molecular typing of Trichophyton mentagrophytes var. interdigitale isolated in a university hospital in Japan based on the non-transcribed spacer region of the ribosomal RNA gene

Detecting intraspecies polymorphisms in fungi causing dermatophytoses is important in elucidating routes of infection and determining whether Tinea recurrence is caused by exacerbation or re‐infection. In fungi, the non‐transcribed spacer region (NTS) of the ribosomal RNA gene shows the greatest accumulation of base sequence mutations. We therefore assessed NTS sequences in 64 clinical isolates of Trichophyton mentagrophytes var. interdigitale, the second most common species of dermatophytes in Japan. These isolates were among the clinical isolates of dermatophytes in the Department of Dermatology, Kanazawa Medical University Hospital in 2006 and were obtained by morphological and molecular biological identification methods. DNA was extracted from each isolate, as well as from one isolate maintained in our department, to detect length polymorphisms at each of three variable loci, TmiS0, TmiS1 and TmiS2, of the NTS for subtyping. We observed seven patterns for TmiS0, six patterns for TmiS1 and three patterns for TmiS2. The combinations of these patterns enabled us to classify the 65 isolates into 15 types. The most prevalent, constituted 46% (30/65) of all isolates. Eleven types were new combinations, whereas the other four were previously described. These results suggest that this method may be used to determine the molecular epidemiology of T. mentagrophytes var. interdigitale in Japan, because it generated results rapidly and in a sensitive manner.

A critical role of Dectin-1 in hypersensitivity pneumonitis

Objectives and designHypersensitivity pneumonitis (HP) is a pulmonary disease caused by repeated exposure to various aspiration antigens, including bacteria and fungi. Although TLRs are known to be required for the generation of HP triggered by bacteria, the significance of fungal receptors remains unclear. The present study aimed to investigate whether Dectin-1 and Dectin-2 contribute to the development of experimental HP triggered by the fungus Trichosporon asahii (T. asahii) that causes summer-type HP.Materials and methodsWe investigated the binding between Dectin-Fc protein and T. asahii by a dot blot assay. We performed the histological and flow cytometric analysis in the HP model using Dectin-1-deficient (Dectin-1−/−) and Dectin-2−/− mice. We also investigated Th17/Th1 responses in lung cells, and measured an IL-17-promoting cytokine IL-23 from bone marrow-derived dendritic cells (BMDCs) by ELISA.ResultsDectin-1 bound more strongly to T. asahii than Dectin-2. Dectin-1−/− mice barely developed HP, whereas both wild-type mice and Dectin-2−/− mice developed similar lung diseases. Dectin-1 deficiency decreased the infiltration of neutrophils and monocyte-derived macrophages and repressed the expansion of lung CD4+IL-17A+ cells. The production of IL-23 p19 was reduced in Dectin-1−/− BMDCs.ConclusionsThese data suggested Dectin-1 plays a critical role in the development of fungus-induced HP.

Case of cutaneous phaeohyphomycosis caused by Phaeoacremonium sp. in a renal transplant recipient

We describe a case of cutaneous phaeohyphomycosis in a 61‐year‐old man receiving re‐dialysis treatment for renal failure of a transplanted kidney. He was immunocompromised with steroid and cyclosporin A at onset of an asymptomatic abscess on his right forearm. The abscess arose at the site of a skin injury approximately 1 year prior. Grayish molds isolated from the lesion were morphologically compatible with Phaeoacremonium sp. but nucleotide sequence data of internal transcribed spacer regions of ribosomal RNA gene, actin and β‐tubulin genes were unlike those of any described species. He was successfully treated with a total of 3 weeks of liposomal amphotericin B, but died of pneumonia approximately 3 months after cure of phaeohyphomycosis.

Glycyrrhetinic acid inhibits contact hypersensitivity induced by trichophytin via dectin-1

Trichophyton infection is highly prevalent and tends to be recurrent. Therefore, it is important to develop new therapeutic agents. Previously, we established a mouse model of Trichophyton‐induced contact hypersensitivity (CHS) and demonstrated that dectin‐1 was involved in inflammation induced by trichophytin, the Trichophyton antigen. Here, we used that model to investigate glycyrrhetinic acid (GA) from plants of the genus Glycyrrhiza as a potential anti‐inflammatory agent against superficial mycoses. GA suppressed swelling and the expression of inflammatory cytokines, including macrophage inflammatory protein (MIP)‐2, interleukin (IL)‐6, tumor necrosis factor (TNF)‐α and interferon (IFN)‐γ mRNA. Anti‐MIP‐2 antibody suppressed trichophytin‐induced inflammation, and antidectin‐1 antibody suppressed zymosan‐induced MIP‐2 production in keratinocyte cells. These results suggest that MIP‐2 is produced by dectin‐1 activation and is involved in inflammation associated with CHS to trichophytin. GA also suppressed zymosan‐induced MIP‐2 and interleukin (IL)‐8, production in mouse and human macrophages and keratinocytes. Furthermore, GA suppressed the phosphorylation of spleen tyrosine kinase (Syk) and inhibitor of nuclear factor‐kappa B (IκBα) and the degradation of IκBα in zymosan‐simulated RAW264.7 cells. The results of this study suggest that GA suppresses inflammation induced by trichophytin, partly by the downregulation of Syk phosphorylation.

The MAT1-1:MAT1-2 Ratio of Sporothrix globosa Isolates in Japan

In order to understand the reproductive biology of pathogenic species in the Sporothrix schenckii complex, we characterized the partial mating type (MAT1-1) loci of Sporothrix schenckii, as well as the S. globosa MAT1-1-1 gene, which encoded 262 amino acid sequences. The data confirmed that the MAT1-1 locus of S. globosa was divergent from the MAT1-2 locus of the opposite mating type, suggesting that the fungus is heterothallic. To determine the mating type ratio of 20 isolates from Japanese patients, we analyzed the MAT loci by specific PCR amplification of MAT1-1-1 and MAT1-2-1 genes. The MAT1-1-1 was detected in 5 isolates but not in the other 15 isolates with the presence of MAT1-2-1. The MAT1-1:1-2 ratio of S. globosa isolates in Japan was estimated to be 1:3. Phylogenetic analysis indicated that the sequences of the MAT1-1-1 were identical among S. globosa isolates but different from S. schenckii and Ophiostoma montium.

Schizophyllum commune-induced allergic fungal rhinosinusitis and sinobronchial mycosis.

We present 32- and 38-year-old males with Schizophyllum commune-induced allergic fungal rhinosinusitis (AFRS). S. commune-induced AFRS was diagnosed by clinical and radiographic findings, positive specific IgE antibodies against S. commune as measured by the ImmunoCAP system, and sequencing analysis of the fungus. Our two cases with S. commune-induced AFRS for the first time showed evidence for type 1 hypersensitivity to S. commune as determined by using specific IgE antibodies against S. commune, and the fungus was identified by sequence analysis.

Molecular Markers Useful for Intraspecies Subtyping and Strain Differentiation of Dermatophytes

Dermatophytosis is a very common skin disorder and the most frequent infection encountered by practicing dermatologists. The identification, pathogenicity, biology, and epidemiology of dermatophytes, the causative agents of dermatophytosis, are of interest for both dermatologists and medical mycologists. Recent advances in molecular methods have provided new techniques for identifying dermatophytes, including intraspecies variations. Intraspecies subtyping and strain differentiation have made possible the tracking of infections, the identification of common sources of infections, recurrence or reinfection after treatment, and analysis of strain virulence and drug resistance. This review describes molecular methods of intraspecies subtyping and strain differentiation, including analyses of mitochondrial DNA and non-transcribed spacer regions of ribosomal RNA genes, random amplification of polymorphic DNA, and microsatellite markers, along with their advantages and limitations.

Polyclonality of Trichophyton rubrum Isolates in aDermatophytosis Patient with Multiple Lesions.

We cultured 15 isolates of Trichophyton rubrum and one isolate of Trichophyton mentagrophytes from an 82-year-old male tinea patient with multiple lesions. To determine whether feet lesions were the source of dermatophytes of other tinea lesions, we extracted total cellular DNA from the T. rubrum isolates（13 from feet, two from right waist and buttock）. PCR targeting the non-transcribed spacer（NTS）region of ribosomal RNA gene was performed. Molecular polymorphisms were detected by length variation of amplicons.Four molecular types were found among the 15 isolates. The predominant type, which we previously named Type III, comprised seven isolates cultured from both feet and from left waist and buttock. This was followed by Type VI, five isolates; Type V, two isolates; and Type IV, one isolate. Apart from type III, which was cultured from both feet, isolates were cultured from one foot only. The patient was successfully treated for all types with a six-month course of oral terbinafine and topical luliconazole. The molecular typing supported the notion that tinea pedis was the source of tinea corporis in the patient.