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.     

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.     

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.     

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.     

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.     

Molecular Analysis of Chitin Synthase 1 (CHS1) Gene Sequences of Trichophyton mentagrophytes Complex and T. rubrum

Nucleotide sequences of chitin synthase 1 (CHS1) gene of dermatophytes, Arthroderma benhamiae, A. simii, A. vanbreuseghemii, Trichophyton mentagrophytes var. interdigitale (T. interdigitale), and T. rubrum were analyzed for their phylogenetic relationship. About 620-bp genomic DNA fragments of the CHS1 gene were amplified from these dermatophytes by polymerase chain reaction (PCR) and sequenced. The CHS1 nucleotide sequences of these five dermatophytes showed more than 90% similarity between the species. The phylogenetic analysis of their sequences revealed that A. benhamiae, A. simii, A. vanbreuseghemii, and T. rubrum were genetically distinct from one another, but T. interdigitale was genetically very close to A. vanbreuseghemii. On the other hand, a specific restriction endonuclease site of HinfI was present in the CHS1 gene fragment of T. rubrum but not in those of A. benhamiae, A. simii, A. vanbreuseghemii and T. interdigitale. The molecular analysis of CHS1 genes will provide useful information for the identification of these Trichophyton species and the understanding of their evolution. Received: 6 March 1998 / Accepted: 4 May 1998     

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.     

Differentiation of trichophyton rubrum from trichophyton mentagrophytes

Conclusions Of the several morphological and physiological criteria that have been proposed to identifyTrichophyton rubrum andTrichophyton mentagrophytes differentially, only the hair invasion test agrees with the immunological results reported here.A typical strain ofT. rubrum andT. mentagrophytes was obtained from the Centraalbureau voor Schimmelcultures (Netherlands) and was used as reference strain. All isolates that did not invade hair shafts (in vitro) and that produced three precipitate lines in agargel diffusion tests against anti-T. rubrum serum (refence strain, Tr-1) were placed in one group. These isolates all also produced a red undersurface pigment and macroconidia with long parallel sides. They were labledT. rubrum.Other isolates that did invade hair shafts, and produced only two precipitate lines against anti-T. rubrum serum were placed in another group and were labeledT. mentagrophytes. These isolates had variable characteristics of pigment production, colony and conidial morphology.The antigenic studies thus corroborate the validity of the hair invasion test. The hair invasion test will probably remain in wider use because of its simplicity.     

Tinea capitis an endemic disease in Madras

A study ofTinea capitis in Outpatient Clinic, Skin Department, Government General Hospital, Madras during a three year period from November, 1973 to October, 1976, has shown a gradual increase in incidence of 3.56%, 5.09 % and 6.25 % respectively. Findings suggest thatTinea capitis is endemic in South India. Male children were more commonly affected than female children and the age groups chiefly affected were between 5 and 10 years. A considerable number of adults were also affected. The disease showed no correlation to environmental temperature, humidity and rainfall but was correlated to all types of mycoses and total incidence of mycoses.Among 357 isolates,Trichophyton violaceum was the commonest in 264 (73.94%) andT. tonsurans was the next common in 47 (13.16%). The other agents wereT. rubrum in 30 (8.4%),T. mentagrophytes in 11 (3.08%) andT. simii in 5 (1.4%). Noninflammatory lesions were more common than inflammatory lesions and both were produced byT. violaceum andT. tonsurans, suggesting strain differences in pathogenesis. Treatment with oral griseofulvin was satisfactory in all but had to be discontinued in 4 patients due to side effects.     

Multicenter study of dermatophyte distribution in the metropolitan area of Barcelona (Catalonia,Spain)

The results of a multicenter study on the distribution of dermatophyte species in the metropolitan area of Barcelona (Spain) are presented.In the period 1977–1983, 638 dermatophyte strains were isolated from tineas by three different mycological laboratories. Zoophilic strains were prevalent comprising 64.4% of the isolates. T. mentagrophytes var. granulosum was isolated in 51% of the cases.A signigicant drop in the prevalence of T. tonsurans and T. violaceum was noted. Important variations were observed in dermatophyte distribution in relation to other geographical areas of Spain.     

<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.     

Ex vivo biofilm-forming ability of dermatophytes using dog and cat hair: an ethically viable approach for an infection model

The aim of this study was to establish an ex vivo model for dermatophyte biofilm growth, using hair from dogs and cats. Strains of Microsporum canis, M. gypseum, Trichophyton mentagrophytes and T. tonsurans were assessed for in vitro and ex vivo biofilm production. All T. mentagrophytes and T. tonsurans isolates and 8/12?M. canis and 1/7?M. gypseum isolates formed biofilms in vitro, while all tested isolates presented biofilm growth on ex vivo models. T. mentagrophytes and M. canis formed more homogeneous and better-structured biofilms with greater biomass production on cat hair but T. tonsurans formed more biofilm on dog hair. Confocal and scanning electron microscopy demonstrated fungal hyphae colonizing and perforating the hair shaft, abundant fungal conidia, biofilm extracellular matrix and biofilm water channels. The present study demonstrated an ex vivo model for the performance of studies on biofilm formation by dermatophytes, using dog and cat hair.     

A survey of dermatophytes isolated from human patients in the United States from 1982 to 1984

A survey of dermatophytes isolated from patients seeking medical advice was made from 1982 to 1984 in the United States. The survey included 59 locations with data from 49 cities and one state. Listing of the isolated dermatophytes and the frequency given by percentage of total follows: Trichophyton rubrum 46.8%, T. tonsurans 33.3%, T. mentagrophytes 10.1%, Microsporum canis 4.5%, Epidermophyton floccosum 3,5%, M. gypseum and T. verrucosum both 0.7%, M. audouinii and T. terrestre both 0.1%, and T. violaceum 0.06%. No isolations of M. ferrugineum or T. schoenleinii were reported.Temporal increases were observed for frequencies of T. mentagrophytes, T. tonsurans and M. canis, and decreases occurred for frequencies of E. floccosum and T. rubrum when the data from this survey were compared by the goodness of fit test to data of the 1979 to 1981 survey. The percent of dermatophyte isolations identified as T. tonsurans correlated significantly with the percentage of blacks in cities of 100000 or more people.     

A survey of dermatophytes from human patients in the United States from 1985 to 1987

A survey of dermatophytes isolated from patients seeking medical advice was made from 1985 to 1987 in the United States. The survey included 54 locations with data from 45 cities and one state. Listing of the isolated dermatophytes and the frequency given by percentage of the total follows: Trichophyton rubrum 54.8%, T. tonsurans 31.3%, T. mentagrophytes 6.0%, Microsporum canis 4.0%, Epidermophyton floccosum 2.0%, M. gypseum 0.6%, and T. verrucosum 0.2%. Out of a total of 14,696 isolates M. audouinii was cultured 13 times, T. violaceum 12 times, M. nanum 6 times, T. terrestre 4 times, and T. soudanense twice. Single isolations were made of M.fulvum, M. ferrugineum and T. schoenleinii.Collection of dermatophyte data in Tucson, Arizona, began in 1966. In 1987, the first case of tinea capitis caused by T. tonsurans was observed. Other isolates of this organism as the cause of tinea capitis were made in this city during that year. These infections were in black children. With the recent growth of Tucson, the percentage of blacks in the population increased and this pathogen was introduced into the general population.     

Forty four years of dermatophytes in a Chicago clinic (1944–1988)

Data are presented on 39270 cultures taken over a 44 year span (1944–1988) at the University of Chicago's Dermatology Clinic. In the mid 1940's Microsporum audouinii accounted for 60–80% of isolates. It gradually decreased over the next two decades and disappeared altogether in the 1970's. Trichophyton rubrum, rare in the 1940's accounted for over 60% of isolates in the mid-1960's only to be overtaken by T. tonsurans. This species, not isolated till the mid 1950's, became and remains the dominant dermatophyte at the present time. Both T. mentagrophytes and Epidermophyton floccosum increased in the 1970's and decreased later. Unusual circumstances resulted in clusters of T. verrucosum, T. terrestre, and T. schoenleinii isolates. Infections were associated with rural dairy workers, zoo handlers and immigrant families respectively. M. canis and M. gypseum were steady at a low rate throughout the entire period. Rare isolates included M. cookei, M. persicolor, M. racemosum, T. simii, T. soudanense, T. violaceum, and the soil keratinophile, Aphanoascus fulvescens.     

Incidence of dermatophytosis in Jordan with special reference to tinea capitis

Clinical data on 1068 cases of dermatophytosis as well as mycological data on 382 of these cases seen from March 1983 to September 1984 are reported. Tinea cruris was present in 34.1%, with Trichophyton rubrum and Epidermophyton floccosum isolated from 31% and 25% respectively. Tinea corporis was found in 17.9% of all patients of dermatophytosis with T. tonsurans responsible in 30.8%. Tinea pedis and Tinea unguium were present in 7.2% and 2% respectively, T. rubrum being the main causative agent; nail involvement was present in 27.3% of these cases. Tinea capitis was observed in 38.7% of 1068 dermatophytosis cases with T. violaceum and M. canis causing 48% and 32% of all T.C. cases respectively.The dermatophytic flora of the West Bank of Jordan apparently comprises about 14 dermatophytes, T. violaceum being the predominant agent of infection (in more than 34%). Other most common agents found in this survey were M. canis, T. rubrum, E. floccosum, T. schoenleini, T. tonsurans, and T. mentagrophytes.Formerly Assistant Professor at the Department of Internal Medicine, Faculty of Medical Sciences, University of Jordan, Amman     

Dermatophytes in Portugal (1972–1981)

For the years 1972–1981, 7 333 isolates of dermatophytes belonging to 14 species were obtained from glabrous skin (32%), feet (28%), groin (19%), scalp (8%), toenails (7%), fingernails (3%) and beard (1%)., T. rubrum represented 50% of all the isolates and was the most frequent species on glabrous skin, groin and nails. T. mentagrophytes (24%) was mainly obtained from the feet, E. floccosum (9%) from the groin and T. megninii (4%) from uncovered areas of the skin, fingernail and beard. These 4 species predominated in men. M. canis was the commonest agent on the scalp and in children up to 11 years. T. violaceum, previously the main cause of tinea capitis, and T. tonsurans have been decreasing for the period of this study, just as T. schoenleinii for the years 1962–71.The rising prevalence of T. rubrum was observed since 1962. In the whole it seems stable after 1969, but the analysis of the main sites involved shows that in the glabrous skin this species increased from 1962 to 1974; in the groin it was gone up from 30% during 1962–1965, to 64% in the years 1969–1971; in the feet the evolution was slower and only in 1980 T. rubrum became more frequent than T. mentagrophytes.The increase in certain species, whereas others become rare, lacks a satisfactory explanation.

---

Résumé Depuis 1972 jusqu'à 1981, 7 333 isolements de dermatophytes concernant 14 espèces ont été obtenus de la peau glabre (32%), des pieds (28%), des plis inguinaux (19%), des ongles des orteils (7%), des ongles des mains (3%) et de la barde (1%). T. rubrum a réprésenté 50% de tous les isolements, étant l'espèce la plus fréquente dans la peau glabre, aux plis inguinaux et dans les ongles. T. mentagrophytes (24%) a été isolé surtout des pieds; E.floccosum (9%) des plis inguinaux; et T. megninii (4%) des régions découvertes de la peau, des ongles de la main et de la barbe. Ces 4 espèces ont prédominé chez des adultes du sexe masculin. M. canis a été l'agent le plus commun dans le cuir chevelu et chez des enfants jusqu'à 11 ans. T. violaceum (auparavant la cause principale des teignes du cuir chevelu) et T. tonsurans sont devenus beaucoup moins fréquents pendant cette étude, comme d'ailleurs T. schoenleinii était devenu rare au cours d'une enquête anterieur (1962–1971).La prévalence de T. rubrum s'est beaucoup elevée dès 1962. Dans l'ensemble, elle parait stabilisée depuis 1969, mais l'analyse des principales localisations de la maladie démontre que dans la peau glabre cette espèce a augmenté depuis 1962 jusqu'à 1974; aux plis inguinaux elle a changé de 30% en 1962–1965 pour 64% en 1969–1971; aux pieds l'évolution a été moins rapide et seulement dès 1980 T. rubrum est devenu plus fréquent que T. mentagrophytes.L'augmentation de certaines espèces tandis que d'autres deviennent rares n'a pas trouvée une interpretation satisfaisante.

     

Deep dermatophytoses in association with atopy anddiabetes mellitus: Majocchi's granuloma tricophyticum ordermatophytic pseudomycetoma?

Two patients presenting with subcutaneous nodules, plaques, papules and ulceration caused by dermatophytes are described in this report. The first case was atopic and had used low dosesystemic corticosteroids intermittently for his asthma. The second case was a poorly controlled and long-standing diabetic patient. The diagnoses were suspected after direct microscopical examinations of the discharge materials which revealed the presence of hyaline hyphae and spores, and histological examination which showed an inflammatory infiltrate with fungal elements in the dermis. Cultures of puncture materials and skin biopsies confirmed the diagnosis identifyingTrichophyton rubrumand T. mentagrophytes var interdigitale,in the first and second case respectively. Antifungal therapy with itraconazole was successful in both patients. The cases are presented to emphasize the possibility of this unusual condition in association with atopy and diabetes mellitus as in profoundly immunosuppressed cases. The nomenclature concerning this type of dermatophyte infections is also discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Characterization of siderophores produced by different species of the dermatophytic fungiMicrosporum andTrichophyton

The dermatophytic fungiTrichophyton spp andMicrosporum spp secrete ferrichrome type siderophores under low iron conditions. Three different species ofMicrosporum, i.e.M. qypseum, M. canis andM. audouinii, as well asT. rubrum produce ferrichrome C and ferricrocin, whereasT. mentagrophytes andT. tonsurans produce only ferrichrome. The identification of the siderophores was established by means of thin layer chromatography, high performance liquid chromatography and mass spectroscopy.     

Review of dermatophytoses in Galicia from 1951 to 1987, and comparison with other areas of Spain

We have reviewed all the dermatophytoses diagnosed in Galicia during four consecutive 9-year periods 1951–86 and 1987. From 4571 patients, we isolated 3351 fungal strains belonging, in decreasing order of frequency, to the following dermatophyte species: Microsporum canis (25.5%), Trichophyton rubrum (24.6%), T. mentagrophytes (21.4%), Epidermophyton floccosum (11.8%), M. gypseum (5.2%), T. tonsurans (3.9%), T. verrucosum (3.1%), T. schoenleinii (2.5%), T. violaceum (1.2%), T. mengninii (0.3%), M. audouinii (0.2%), T. equinum (0.1%) and T. soudanense (0.1%). Tinea capitis has diminished in frequency since 1951, though there was been a slight increase since 1978; M. canis has always been the most common agent, and between 1951 and 1959 T. schoenleinii was also very frequent but is no longer found. The frequency of tinea corporis, on the other hand, has experienced a considerable increase. Its most common causal agents in the last few years have been T. mentagrophytes, M. canis and T. rubrum. Until 1977 the most common tinea cruris dermatophyte was E. floccosum, but since then it has been T. rubrum. The commonest tinea pedis dermatophytes have been T. rubrum and T. mentagrophytes. Tinea unguium and tinea barbae have been the most frequent dermatophytoses, and their commonest causal agents T. rubrum and T. mentagrophytes respectively. We have documented the distribution of the various causal agents by location of the lesions, age and source of the patients (private or National Health Service patients), and we have compared the results with those obtained in other regions of Spain.