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.     

Favus of the Scalp: An Overview and Update

Tinea capitis favosa, a chronic inflammatory dermatophyte infection of the scalp, affects over 90% of patients with anthropophilic Trichophyton schoenleinii. T. violaceum, T. verrucosum, zoophilic T. mentagrophytes (referred to as ‘var. quinckeanum’), Microsporum canis, and geophilic M. gypseum have also been recovered from favic lesions. Favus is typically a childhood disease, yet adult cases are not uncommon. Interestingly, favus is less contagious than other dermatophytoses, although intrafamilial infections are reported and have been widely discussed in the literature. Clinical presentation of T. schoenleinii infections is variable: this fungus can be isolated from tinea capitis lesions that appear as gray patches, but symptom-free colonization of the scalp also occurs. Although in the past T. schoenleinii was the dominant fungus recovered from dermatophytic scalp lesions, worldwide the incidence has decreased except in China, Nigeria, and Iran. Favus of the glabrous skin and nails are reported less frequently than favus of the scalp. This review discusses the clinical features of favus, as well as the etiological agents, global epidemiology, laboratory diagnosis, and a short history of medical mycology.     

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.     

A short review on dermatophytoses of animals in Romania

Dermatophytoses of animals in Romania are reviewed. Ringworm infections have been found in cattle (whereT. verrucosum was the only isolated agent), horses (the causative organisms beingT. verrucosum, T. mentagrophytes andM. equinum), cats (dermatophytes isolated:M. canis andT. quinckeanum), dogs (M. canis andM. gypseum), fowlsT. gallinae). From the laboratory animals: guinea pigs (T. mentagrophytes, M. audouinii, T. rubrum), mice (T. quickeanum andT. mentagrophytes), rats (T. mentagrophytes), rabbits (T. mentagrophytes andM. canis) and hamster)T. mentagrophytes). Among the wild animals, only the chamois had a ringworm infection byM. gypseum, other large or smaller wild animals harboring only saprophytically some poozhilic and geophilic dermatophytes.     

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.     

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.     

Effect of visible light on carotenogenesis in arthroconidiating Trichophyton mentagrophytes

The effect of visible light on carotenoid content in the dermatophyte Trichophyton mentagrophytes ATCC 26323 was investigated. The fungus T. mentagrophytes accumulated several carotenoids when arthroconidiated on Sabouraud glucose agar at 37°C. When this fungus was irradiated with moderate fluence rates of white light, the resultant arthroconidia contained considerably less carotenoids in comparison with dark controls although growth and arthroconidiation of this fungus were not at all affected by visible light. The reduction of carotenoid content in arthroconidia was due primarily to blue light, although red light caused a slight decrease in pigmentation. The suppressive effect of visible light on pigmentation was fluence rate dependent. Carotenoid accumulation in arthroconidia was inversely and exponentially related to the fluence rate of light. Carotenoid formation in arthroconidiating T. mentagrophytes was neither photoinducible nor photostimulative. An analysis of isolated carotenoids revealed that visible light caused a quantitative reduction in pigmentation, and no single carotenoid was selectively decreased.Non-standard abbreviations PI pigmentation index - r coefficient of correlation     

Exocellular enzyme activity of dermatophytes and other fungi isolated from ruminants in Southern Iraq

Sixteen fungal species were isolated from 182 specimens collected from four ruminants (buffalo, camel, cattle and sheep) in Southern Iraq. Fungi represented by five species of dermatophytes and eleven species of other fungi were screened for the activity of four enzymes; keratinase, proteinase, lipase and amylase. Keratinase was found to be produced by all of the dermatophytes and non-dermatophytes, except for Paecillomyces variottii and Scytalidium lignicola. However, high keratinase activity was expressed by the dermatophytic species particularly by Trichophyton mentagrophytes var. erinacei and Microsporum gypseum. Three dermatophytes viz. M. gypseum, T. verrucosum and T. mentagrophytes var. nodulare were capable of producing protease, lipase and amylase. Although, T. mentagrophytes var. erinacei showed high protease activity, it did not produce lipase and amylase. On the contrary most of the non-dermatophytic species revealed protease and lipase activities higher than the dermatophytes. The Curvularia spp. isolates showed the highest protease and amylase activity, while Aspergillus parasiticus revealed the highest activity of lipase and amylase. No correlation was observed between enzyme activity and the growth rate of the examined fungi. This revised version was published online in June 2006 with corrections to the Cover Date.     

A short review on the onychomycoses by dermatophytes in Romania

In 525 patients with onychomycoses by dermatophytes, collected in Bucharest (45% of the cases being females), the toe-nails were found to be affected in 65% of the cases, while the finger-nails only in 20%. In order of frequency, the following agents were isolated:T. rubrum (55%),T. mentagrophytes (interdigitale — 26%),T. violaceum (12%),E. floccosum (3%),T. schonleinii (1.3%). Only sporadically were found other species, viz.:M. canis (4),T. tonsurans (3),T. verruccosum (2),T. quinckeanum (1) andM. audouinii (1). Tinea pedis was the main manifestation associated with the respective cases.     

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.     

Ringworm in rabbit due to Trichophyton quinckeanum

Summary Trichophyton quinckeanum was isolated from a spontaneous infection in rabbit. The hairs were also invaded by the fungus, exibiting a yellowish fluorescence in Wood's light. White mice inoculation of the isolate produced typical scutula with hair penetration fluorescing in green colour. The type of animal hair invasion is also discussed. The morphologic features ofTr. quinckeanum, together with its ability of producing scutula while inoculating the white mice, must be emphasized, when proving its separate identity.     

Biolarvicidal activity of extracellular metabolites of the keratinophilic fungus <Emphasis Type="Italic">Trichophyton mentagrophytes</Emphasis> against arvae of <Emphasis Type="Italic">Aedes aegypti</Emphasis> — a major vector for Chikungunya and dengue

The larvicidal activity of extracellular metabolites of keratinophilic fungus Trichophyton mentagrophytes against Aedes aegypti larvae was determined. T. mentagrophytes was isolated from soil by the feather baiting technique. Culture filtrates (10–100 μL/mL) were found to be entomotoxic to 3rd instars larvae of A. aegypti (L3), LC₅₀ and LC₉₀ being 110 ± 11.5 and 200 ± 20.7 μL/mL, respectively, after 2 d. Extracellular metabolites are proteinaceous in nature and more specific to chitin of mosquito larvae. They degraded cock feather causing an average of 20.0 ± 2.6 % loss in feather mass. Culture filtrate at 100 μL/mL produced 90 % mortality against L3 after 3 d; mortality was increased in dose- and time-dependent manner. These extracellular metabolites of T. mentagrophytes could be regarded as alternatives to synthetic insecticides.     

Sur l'origine tellurique du Ctenomyces inter-digitalis (Epidermophyton Kaufmann-Wolf). Dysidrose palmaire par contact avec de la terre

Summary The authors were able to isolate from the superficial layers of the soil,Ctenomyces interdigitalis (Epidermophyton interdigitale, Epidermophyton Kaufmann-Wolf). The morphological macro- and microscopical features of the cultures, as well as those of the experimental lesions, obtained by inoculation in man and animal, proved that the isolated fungus was reallyCtenomyces interdigitalis and notCtenomyces mentagrophytes orTrichophyton (Achorion)quinckeanum. The isolated strain caused a dysidrosis of the palm. The patient, a woman 34 years old, infected herself by scooping with her left hand the earth mixed with dead (withered) leaves which were found in a watering pond. The authors did not find, up to now in the literature, any mention about the presence of this dermatophyte in the soil, which would be proved by direct investigation, although its presence in this medium was accepted by those who observed tinea pedis developing after the contact of the feet with the earth.

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Résumé Les auteurs ont réussi à isoler, de la terre, leCtenomyces interdigitalis (Epidermophyton interdigitale, Epidermophyton deKaufmann-Wolf). Les caractères morphologiques, macro- et microscopiques des cultures, ainsi que ceux des lésions expérimentales, obtenues par son inoculation à l'homme et à l'animal, ont précisé qu'il s'agissait bien duCtenomyces interdigitalis et non duCtenomyces mentagrophytes ou duTrichophyton (Achorion)quinckeanum. La souche isolée avait provoqué une dysidrose palmaire chez une femme âgée de 34 ans. La malade s'est contaminée en creusant, de sa main gauche, la terre mélangée à des feuilles mortes qui se trouvait dans une bouche d'arrosage. D'après la littérature consultée, il semble que ce dermatophyte n'a pas été isolé, directement, jusqu'à présent, des couches superficielles du sol, bien que sa présence dans ce milieu fut admise par nombre d'auteurs qui ont vu l'Epidermophytie plantaire se développer après le contact, des pieds nus, avec la terre.

     

Dermatophytes in a population of bank voles and woodmice

A population of bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus) inhabiting an oak wood in Somerset was examined for dermatophytes at monthly intervals for 2 years. The marked animals were frequently retrapped, allowing a study of host fungus relationship over a period of time. Microsporum persicolor (Sabouraud) Guiart er Grigorakis and Trichophyton mentagrophytes (Robin) Blanchard were isolated from both animal species, but M. persicolor predominated in bank voles and T. mentagrophytes in wood mice. In their most favoured host, both dermatophyte species often persisted for several months, but in the less favoured host they were never isolated at more than one sampling. Males of both animal species were infected more often than females.The existing evidence for the geophilic nature of both fungi is reviewed and shown to be very weak, especially for M. persicolor.This is the first report from Great Britain of T. mentagrophytes infection of wood mice not in contact with human habitation.     

Sur la présence du Trichophyton (Achorion) quickeanum dans le sol

Résumé En continuant leurs recherches, en vue de contribuer à l'élucidation du problème concernant la nature saprophytique, tellurique, des dermatophytes, les auteurs ont réussi, en utilisant le procédé deVanbreuseghem, à isoler du sol leTrichophyton quinckeanum. Ils l'ont mis en évidence dans la terre qui se trouvait sous un petit abri pour le bois, abri situé près d'une maison à Bucarest. La même souche avait provoqué un herpès circiné inflammatoire chez une femme qui s'est probablement contaminée en fendant le bois sous ce même abri. La souche isolée de la terre a été inoculée, avec résultat positif, à l'homme, au cobaye et à la souris blanche. Chez l'homme, la mycose expérimentale a été accompagnée par l'apparition de godets visibles à l'oeil nu (dans un seul cas).Selon les auteurs, il serait utile de chercher systhématiquement, dans les couches superficielles du sol, tous les dermatophytes à cultures vivaces et à riche morphologie microscopique, vu qu'ils ont isolé, de la même terre et en même temps que leTrichophyton quinckeanum (et en même temps que leMicrosporon gypseum et leKeratinomyces ajelloi) leTrichophytron terrestre proche auCtenomyces mentagrophytes.

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Summary In continuing their researches in order to contribute to the elucidation of the problem concerning the presence of dermatophytes as saprophytes in the soil, the authors were able to isolate from the soil, making use ofVanbreuseghem's method, a strain ofTrichophyton (Achorion)quinckeanum. The very difficult isolation of this fungus has been done from the soil of a woodshed, in a court of a house in Bucarest. The same strain caused a herpes circinatus of inflammatory type, on the wrist of the woman to whom the shed belonged. This woman probably contaminated herself by spliting wood there. The strain, isolated from the soil, was inoculated in man, guinea pig and white mouse, with positive results. In one case, the experimental lesion, obtained in man, showed the presence of little scutula. Considering that lately they were able to isolate from the soil, not only the above mentionedTrichophyton quinckeanum (in addition toMicrosporon gypseum andKeratinomyces ajelloi) but also theTrichophytron terrestre, near toCtenomyces mentagrophytes, the authors think that it would be useful to persist in searching farther, in the superficial layers of the soil, for the presence of the dermatophytes with rich microscopical morphology.

     

A ten years survey of Romanian soil screening for keratinophilic fungi (1958–1967)

Summary Out of 750 soil samples collected from various regions of Romania, during 1958–1967, a positive percentage of 86 was positive for keratinophilic fungi. Among the 13 isolated species, the most prevalent wereM. gypseum (54.6 %),C. keratinophilum (40.1 %) andK. (T.)ajelloi (27 %). BesideT. terrestre, found in 8.9 % of the examined soil samples, the percentage of the remaining species is low, not exceeding 4 %. In order of frequency:C. (T).evolceanui (3.2 %),M. cookei (2.2 %),T. mentagrophytes (2 %),T. quinckeanum (0.9 %),C. (T.)indicum (0.6 %). There have been also isolated, but only once;M. canis, A. multifidum, T. georgiae andT. vanbreuseghemii.The studies carried out on the immunobiological properties of the Romanian soil isolates (including intracutaneous tests, serological reactions and therapeutic efficiency), have showed a close relationship between these fungi and the common pathogenic dermatophytes. The pathogenic power of the keratinophilic fungi is briefly discussed.     

In vitro hair cultures for differentiating between atypical isolates ofTrichophyton mentagrophytes andTrichophyton rubrum

Summary Isolates ofT. mentagrophytes andT. rubrum are encountered that cannot be distinguished from each other solely on the basis of morphological criteria.Since these two species fundamentally differ in the manner in which they attack hairin vitro, this property can be used as a diagnostic aid, when correlated with their morphologic characteristics as developed on a variety of media. T. mentagrophytes radially penetrates hair segments immersed in water forming wedge-shaped perforations.T. rubrum does not perforate hair.The method of determining the ability or inability ofT. mentagrophytes orT. rubrum to perforate hair and the use of this test in identifying those species are described.     

Repeated Ubiquitin Genes in Trichophyton mentagrophytes

Using Trichophyton mentagrophytes cDNA as a template, we performed PCR amplification with the UB1S and UB1R primers for isolation of a partial fragment of T. mentagrophytes ubiquitin gene. We screened the T. mentagrophytes cDNA library prepared with Uni-ZAP phage vector by hybridization with the T. mentagrophytes ubiquitin fragment, UB1S-UB1R. The nucleotide and deduced amino acid sequences of T. mentagrophytes ubiquitin gene encoded two ubiquitin repeats in 162 bp to 624 bp. The deduced amino acid sequences of ubiquitin from T. mentagrophytes shared about 98% similarity with those of Saccharomyces cerevisiae, Neurospora crassa, and Cryptococcus neoformans. Received: 28 April 1999 / Accepted: 22 June 1999     

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.     

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.