The First Isolation of Arthroderma benhamiae in Japan

A clinical isolate of Trichophyton mentagrophytes from rabbit was examined by polymerase chain reaction (PCR) analysis and a mating experiment. The species-specific primers designed from the nucleotide sequences of the chitin synthase 1 (CHS1) gene in the teleomorph of Arthroderma benhamiae amplified a fragment from genomic DNA samples of A. benhamiae and the clinical isolate but not from those of A. simii and A. vanbreuseghemii. On the other hand, the species-specific primers of A. simii and A. vanbreuseghemii did not amplify any fragment from the genomic DNA of the clinical isolates. When the isolate was respectively crossed with (+) or (-) tester strains of A. benhamiae, A. simii and A. vanbreuseghemii, ascospores were produced in the crossing with the A. benhamiae (+) strain. Therefore, the isolate was identified to be A. benhamiae (-), confirming the result of molecular analysis. This is the first report on the isolation of A. benhamiae in Japan.     

Phylogeny of the genera Trichophyton using mitochondrial DNA analysis

Diversity of mitochondrial DNA (mtDNA) was investigated in 92 Trichophyton rubrum strains, 2 T. mentagrophytes var. mentagrophytes, 2 T. m. vor. interdigitale, 2 T. m. var. goetzii, 1 T. m. var. erinacei, 2 T. quinckeanum, 2 T. schoenleinii, 1 T. tonsurans, 2 T. verrucosum var. album, 2 T. v. var. discoides, 1 T. violaceum var. violaceum, 1 Arthroderma benhamiae, and 1 A. vanbreuseghemii using endonucleases, Hae III, Msp I, Hind III, Xba I, and Bgl II. Trichophyton species were divided into 7 groups, and a phylogenetic tree was produced based on sequence divergence within mtDNA. The following results were obtained: (1) T. rubrum was divided into 2 groups Type I and Type II, and was suggested to be a complex. (2) A. benhamiae was closely related to T. m. var. erinacei. (3) T. rubrum Type II, T. tonsurans, and A. vanbreuseghemii showed identical restriction profiles, and were suggested to be closely related to each other or identical. (4) T. quinckeanum and T. schoenlenii showed identical restriction profiles, which differed slightly from those of A. vanbreuseghemii. (5) mtDNA analysis was useful in identifying pleomorphic strains.     

Molecular confirmation of a Trichophyton violaceum isolate from human black-dot ringworm

A clinical isolate from a black-dot ringworm lesion of a 28-year-old female Japanese was investigated by morphological and biochemical analyses as well as molecular analyses. The isolate grew well onthiamine enriched agar and did not produce violetpigment, macroconidia or microconidia on Sabouraud's dextrose agar. Approximately 620-bp genomic DNA fragments of the CHS1 gene were amplified from Trichophyton mentagrophytes, T. rubrum, T. tonsurans and T. violaceum by polymerase chain reaction (PCR) and sequenced. The chitin synthase 1 (CHS1) nucleotide sequences of the clinical isolate showed more than 97% similarity to that of T. violaceum and less than 96% similarity to that of T. mentagrophytes, T. rubrum and T. tonsurans. The phylogenetic analysis of their sequences revealed that the clinical isolate was genetically close to T. violaceum and distinct from T. mentagrophytes, T. rubrum and T. tonsurans. Therefore, the isolate was confirmed as T. violaceum by mycological examination and molecular analyses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Molecular taxonomy of dermatophytes and related fungi by chitin synthase 1 (CHS1) gene sequences

In the present study, the nucleotide sequences of the CHS1 gene from dermatophytes and related fungi in the genera Chrysosporium, Epidermophyton, Microsporum and Trichophyton were investigated using molecular methods. About 440-bp genomic DNA fragments of the CHS1 gene from 21 species were amplified by polymerase chain reaction (PCR) and sequenced. The CHS1 nucleotide sequences of these fungi showed more than 83% similarity. The molecular taxonomy of the CHS1 gene sequences revealed that Microsporum was genetically distinct from Chrysosporium and Trichophyton, as classified by morphological characteristics. This revised version was published online in June 2006 with corrections to the Cover Date.     

Phylogenetic relation of Epidermophyton floccosum to the species of Microsporum and Trichophyton in chitin synthase 1 (CHS1) gene sequences

The Nucleotide sequence of the chitin synthase1 (CHS1) gene of Epidermophyton floccosum, an anthrophophilic dermatophyte which is the type species of the genus Epidermophyton was analyzed to determine its phylogenetic relation to eight other dermatophyte species belonging to the genera Microsporum and Trichophyton, which were sequenced in our previous studies. A genomic DNA fragment about 620 bp in length of the CHS1 genewas amplified from E. floccosum by polymerasechain reaction (PCR) and was sequenced. The CHS1 nucleotide sequence showed more than 85% similarity with sequences derived from the other dermatophytes. Phylogenetic analyses of the sequences from E. floccosum revealed that the genus Epidermophyton may be genetically distinct from Microsporum and Trichophyton. This revised version was published online in June 2006 with corrections to the Cover Date.     

Mating patterns of dermatophytes of diverse origin in India

The mating patterns of Trichophyton mentagrophytes var. interdigitale (74 isolates) and the Microsporum gypseum complex (17 isolates) of diverse origin and T. rubrum (25 isolates) and T. tonsurans (10 isolates) of clinical origin were studied. The results of the study showed that the teleomorph of the Indian isolates of T. mentagrophytes belong to Arthroderma vanbreuseghemii, undetermined teleomorphs of T. mentagrophytes var. interdigitale (+) mating types, and undetermined teleomorphs of T. mentagrophytes var. interdigitale indeterminate mating types. All the isolates of T. rubrum and T. tonsurans were found to be of the (-) mating type.     

Hybridization and sexual stimulation inTrichophyton mentagrophytes

Mating and sexual stimulation tests applied to 132 strains of this dermatophyte isolated in Czechoslovakia revealed among them strains ofArthroderma benhamiae (40 strains of the+mating type, one of the—mating type) andA. vanbreuseghemii (three strains of the+type, seven of the-type). No dependence was found concerning the anamorphic variety (T. mentagrophytes var.granulosum, var.interdigitale, var.mentagrophytes, var.quinckeanum), teleomorphic species, mating type and the clinical localization of dermatophytosis. Plausible reasons of different frequencies of the mating types are discussed.     

<Emphasis Type="Italic">Trichophyton rubrum</Emphasis> and <Emphasis Type="Italic">Trichophyton interdigitale</Emphasis>: Genetic Diversity Among Species and Strains by Random Amplified Polymorphic DNA Method

Onychomycosis is a common condition that represents up to 50% of all nail problems and 30% of all cases of dermatophytoses. Trichophyton rubrum and Trichophyton interdigitale are the most common agents involved in this condition. In cases of recurrent post-treatment onychomycosis, strain fingerprinting could reveal whether the original isolate is responsible, a new strain has been acquired or if multiple strains are involved. The aim of this study was to evaluate the efficacy of the RAPD method for species and strain differentiation of T. rubrum and T. interdigitale obtained from patients with subungeal distal-lateral onychomycosis. A set of 86 strains of onychomycosis causative dermatophytes were submitted to species differentiation and strain typing by RAPD method with two previously described primers. Both primers proved capable of strain differentiation when tested for each species. Nineteen molecular profiles were configured for T. rubrum isolates with primers 1 and 6. For T. mentagrophytes, ten molecular profiles were configured with primer 1 and twenty-one with primer 6. We found that T. interdigitale and T. rubrum species were grouped in different clusters when both primers were analyzed together. This study shows that these primers are valuable tools for strain differentiation with T. rubrum and T. intedigitale.     

Effective photodynamic treatment of Trichophyton species with Rose Bengal

Photodynamic therapy (PDT) with Rose Bengal has previously achieved eradication of Trichophyton rubrum infections causing toenail onychomycosis; however, its antifungal activity against other clinically relevant dermatophytes has yet to be studied. Here, we test the efficacy of PDT using Rose Bengal (140 μM) and 532 nm irradiation (101 J/cm²) against Trichophyton mentagrophytes and Trichophyton interdigitale spores, in comparison to T. rubrum. A significant reduction (>99%) of T. mentagrophytes and T. interdigitale was observed, while actual eradication of viable T. rubrum was achieved (99.99%). Laser irradiation alone inhibited growth of T. rubrum (55.2%) and T. mentagrophytes (45.2%) significantly more than T. interdigitale (25.5%) (P = .0086), which may indicate an increased presence of fungal pigments, xanthomegnin and melanin. The findings suggest that Rose Bengal-PDT can act against a broader spectrum of fungal pathogens, and with continued development may be employed in a wider range of clinical antifungal applications.     

Sur l'état actuel des dermatophytes en Roumanie

Summary The actual state of dermatophytes in Romania is briefly reviewed. From the 20 species discovered, up to now, 14 belonged to the group of human and animal origin, the other 6 to geophilic dermatophytes.The most frequently isolated wereT. mentagrophytes, (var.interdigitale),M. audouinii, T. violaceum andT. rubrum, which altogether caused more than 50 % of the human ringworm found in the last 15 years.WhileT. mentagrophytes still remains the agent no. 1 of tinea pedis in Romania andT. rubrum keeps the first place in the nail involvements by dermatophytes, the first organism of tinea capitis areM. audouinii andT. violaceum, the former causing mainly the epidemic foci. Such epidemics may also be due toT. ferrugineum. The number of cases byT. schönleinii is more and more reduced. The infections byT. verruccosum are increasing. The rarity of cases due toT. gallinae, toT. equinum and toT. mengninii are pointed out.From the so called geophilic dermatophytes,M. gypseum, K. ajelloi andChrysosporium keratinophilum are mostly isolated from the Romanian soil.T. terrestre, T. evolceanui, T. indicum andM. cookei are infrequently found. A few isolates ofT. mentagrophytes andT. quinckeanum were also discovered in the soil.     

Updating the Taxonomy of Dermatophytes of the BCCM/IHEM Collection According to the New Standard: A Phylogenetic Approach

Recent taxonomical revisions based on multilocus gene sequencing have provided some clarifications to dermatophyte (Arthrodermataceae) family tree. These changes promoted us to investigate the impact of the changed nomenclature of the dermatophyte strains in the BCCM/IHEM fungal collection, which contains strains of all dermatophyte genera except for Ctenomyces. For 688 strains from this collection, both internal transcribed spacer region (ITS) and partial β-tubulin (BT) sequences were aligned and a multilocus phylogenetic tree was constructed. The ITS?+?BT phylogentic tree was able to distinguish the genera Arthroderma, Lophophyton, Microsporum, Paraphyton, Nannizzia and Trichophyton with high certainty. Epidermophyton, which is widely considered as a well-defined genus with E. floccosum as the only representative, fell within the Nannizzia clade, whereas the phylogenetic analysis, based on the ITS region alone, differentiates Epidermophyton from Nannizzia as a separate genus. Re-identification and reclassification of many strains in the collection have had a profound impact on the composition of the BCCM/IHEM dermatophyte collection. The biggest change is the decline of prevalence of Arthroderma strains; starting with 103 strains, only 22 strains remain in the genus after reassessment. Most Arthroderma strains were reclassified into Trichophyton, with A. benhamiae and A. vanbreuseghemii leaving the genus. The amount of Microsporum strains also dropped significantly with most of these strains being reclassified into the genera Paraphyton and Nannizzia.

     

Dermatophyte species,microscopic and cultural examination

The dermatophytes Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes var. interdigitale, T. rubrum, and T. verrucosum were compared with respect to the direct microscopic examination of a clinical material and the number of colonies obtained by culture.It was found that the results of microscopy as well as of culture depended to a marked extent upon which species were the cause of the mycosis.The extremes were E. floccosum and T. mentagrophytes var. interdigitale which showed 7.5 % and 32.5 % isolates with negative microscopic findings and 45.5 % and 5.0 % isolates with 10 colonies.     

The Changing Face of Dermatophytic Infections Worldwide

Dermatophytes evolve along with the geography and socioeconomic conditions. Epidermophyton floccosum, Microsporum audouinii and Trichophyton schoenleinii acted as the major pathogens of superficial fungal diseases 100 years ago, but their frequency decreased dramatically since the middle of the twentieth century and they are limited to some less-developed countries nowadays; meanwhile, frequency of Trichophyton rubrum, Trichophyton interdigitale, Trichophyton tonsurans and Microsporum canis increased gradually, and these fungi have become the major species globally. Some other dermatophytes, i.e., Trichophyton violaceum, Trichophyton verrucosum and Microsporum ferrugineum, are mainly endemic in some parts of Africa, Asia and Europe. At present, T. rubrum is the leading pathogen for skin and nail fungal infections, whereas M. canis, T. tonsurans and T. violaceum present as the predominant dermatophytes involved in tinea capitis. Population mobility, changes in human lifestyle and advents of antifungal drugs will continually drive the dermatophyte evolution in the skin microenvironment. Comprehensive observation is needed to better understand this kind of organisms and prospect the trends of their changes in future.     

Chitin synthase 2 gene sequence of Malassezia species.

Nucleotide sequences of the chitin synthase 2 (CHS2) gene of seven species, Malassezia furfur, M. globosa, M. obtusa, M. pachydermatis, M. restricta, M. slooffiae and M. sympodialis, were analyzed for their phylogenetic relationship. About 620-bp genomic DNA fragments of the CHS2 gene were amplified from these Malassezia species by polymerase chain reaction (PCR) and sequenced. The CHS2 nucleotide sequences of these Malassezia species showed more than 95% similarity between the species. A phylogenetic analysis of the nucleotide sequences of CHS2 gene fragments of seven Malassezia species revealed that the species were genetically distinct from each other.     

In vitro susceptibility of dermatomycoses agents to six antifungal drugs and evaluation by fractional inhibitory concentration index of combined effects of amorolfine and itraconazole in dermatophytes

To investigate the antifungal drug susceptibility of fungi responsible for dermatomycoses, minimum inhibition concentration (MIC) tests were performed in 44 strains of dermatophytes, including Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton verrucosum, Trichophyton tonsurans, Microsporum canis, Microsporum gypseum and Epidermophyton floccosum, with six antifungal drugs (amorolfine, terbinafine, butenafine, ketoconazole, itraconazole and bifonazole) by broth microdilution assay according to Clinical Laboratory Standard Institute protocols. Six possible dermatomycosis‐causing non‐dermatophytic fungi were also tested. The two major causes of tinea, T. rubrum and T. mentagrophytes, showed significantly different sensitivities to ketoconazole and bifonazole. Clinically derived dermatophytes were sensitive to the six antifungal drugs tested. However, non‐dermatophytes, especially Fusarium spp., tended to be resistant to these antifungal drugs. In Trichophyton spp., the MICs of non‐azole drugs had narrower distributions than those of azoles. To evaluate the effects of antifungal drug combinations, the fractional inhibitory concentration index was calculated for the combination of amorolfine and itraconazole as representative external and internal drugs for dermatophytes. It was found that this combination had synergistic or additive effects on most dermatophytes, and had no antagonistic effects. The variation in susceptibility of clinically derived fungal isolates indicates that identification of causative fungi is indispensable for appropriately choosing effective antifungal drugs in the early stages of infection. The results of combination assay suggest that multiple drugs with different antifungal mechanisms against growth of dermatophytes should be used to treat refractory dermatomycoses, especially onychomycosis.     

Dermatophytes isolated from patients in University Hospital,Kuala Lumpur,Malaysia

A total of 576 dermatophytes were isolated from patients with a variety of skin infections from January 1993 to May 2000. Ten species of dermatophytes were identified: Epidermophyton floccosum (0.7%), Microsporum audouinii (1.1%), M. canis (3.1%), M. gypseum (0.3%), Trichophyton concentricum(3.5%), T. equinum (0.2%), T. mentagrophytes (36.%), T . rubrum (53.8%), T. verrucosum (0.2) and T. violaceum (1.0%). The body sites most frequently affected by dermatophytes were the buttocks, nails and trunk. Anthropophilic dermatophytes made up 60.1% of the isolates; the most common species was T. rubrum, T. mentagrophytes and M. canis were the two main zoophilic dermatophytes. T. mentagrophytes was isolated from all body sites except the scalp. M. canis was found to be associated with domestic dogs and wasnot isolated from ethnic Malays. The only geophilic dermatophyte was M. gypseum, an uncommon dermatophyte associated with tinea pedis.This revised version was published online in October 2005 with corrections to the Cover Date.     

Trichophyton simii infections in chickens,dogs and man in India

The clinical, mycological and epidemiological aspects of naturally occurringTrichophyton simii infections in chickens, dogs and man are described. Nineteen strains ofT. simii, were isolated (16 from chickens, 2 from dogs and one from man). None of 16 soil samples from these localities were positive forT. simii, although two soil samples yieldedMicrosporon gypseum.     

Lineages Within the Trichophyton rubrum Complex

The most important species of the Trichophyton rubrum group are T. rubrum, causing mainly skin and nail infections, and T. violaceum which is mostly scalp-associated. The status of a third species, T. soudanense, has been under debate. With a polyphasic approach, using molecular phylogenetic techniques, MALDI-TOF mass spectrometry and physiological and morphological analysis, we re-evaluated the T. rubrum complex. Our results support four genetic lineages within the complex each with a distinct morphology and identifiable via MALDI-TOF MS: T. rubrum, T. violaceum, T. soudanense and the T. yaoundei clade. However, ITS and Bt2 sequencing data could not confirm these taxa as four monophyletic species. Our results also suggest that strains formerly identified as T. kuryangei and T. megninii should be considered in future taxonomic studies.

     

Enzyme make-up of trichophyton rubrum and t. mentagrophytes

Summary Aldolase activity in the cell-free extracts of two dermatophytes,T. mentagrophytes andT. rubrum, was investigated. The kinetics of the enzyme and the effects of metal ions and metal-binders are also reported. The enzyme was more active inT. mentagrophytes than inT. rubrum. The optimum pH for the enzyme action was 7.2 and it was completely inactivated at 60° C. Cobalt and magnesium ions and cysteine activated the enzyme. Inhibition caused by EDTA and o-phenanthroline was partially reversed by cobalt ions. The dermatophyte aldolase resembles bacterial aldolase in its properties.