Identification and genetic homogeneity of Trichophyton tonsurans isolated from several regions by random amplified polymorphic DNA

Trichophyton tonsurans is an anthropophilic dermatophyte mostly causing tinea capitis and tinea corporis. This study was carried out to identify T. tonsurans and to clarify whether it has any genetic differences depending on the phenotype or region of isolation by random amplified polymorphic DNA (RAPD) analysis with three random primers. The assay was performed in 11 Korean, 2 Japanese, 2 Taiwanese, 5 Brazilian and 1 American isolates of T. tonsurans together with the other 10 anamorphic species of dermatophytes and 3 Arthroderma spp. All tested species of dermatophytes showed distinct bands and T. tonsurans was differentiated from other dermatophytes. It was most clearly ifferentiated from T. mentagrophytes by using primer 5-GAAGGCTCCC-3 (OPAO-15). No difference was found in RAPD band patterns in all strains of T. tonsurans with these random primers. It was considered that T. tonsurans is a genetically homogeneous species regardless of its isolation regions, morphologic or physiologic characteristics.This revised version was published online in October 2005 with corrections to the Cover Date.     

Lipolytic activity of dermatophytes

Lipolytic activity of dermatophytes was tested by the method generally used forCandida lipolytica. Most of the freshly isolated strains ofMicrosporum canis, M. gypseum, Epidermophyton floccosum andTrichophyton mentagrophytes gave positive reactions, whereas, only few strains ofT. schoenleini, T. violaceum, T. megnini, T. rubrum andT. tonsurans yielded such reactions. Among subcultured strains, it was found a decreased lipolytic activity inMicrosporum species and an increased lipolytic activity inEpidermophyton and someTrichophyton species.Part of this work was performed at Serviço de Doenças Infecto-Contagiosas (Secção de Dermatologia), Hospital de Curry Cabral - Lisboa.     

Solanum melongena: A potential source of antifungal agent

The antifungal activity of Solanum melongena leaf, extracted with petroleum ether, chloroform, methanol and water was evaluated against three human pathogenic dermatophytes namely Trichophyton mentagrophytes, T. rubrum and T. tonsurans and two opportunistic fungi Candida albicans and Trichosporon beigelii. Maximum yield of plant components was 4.32 g, extracted in water and minimum 1.07 g in petroleum ether from 150 g of dry plant material. Except water extract, all the extracts possessed significant antifungal property. All the test pathogens showed highest sensitivity towards chloroform extract, exhibiting maximum inhibition zone diameter of 50.0 mm in T. mentagrophytes and minimum 30.0 mm in C. albicans at 2 × 10⁵ μg/ml concentration. Chloroform extract at lower concentration 2.5 × 10⁴ μg/ml was inhibitory for all the test pathogens, exhibiting inhibition zone diameter 21.0 mm against T. tonsurans and 15.0 mm against C. albicans and T. beigelii. The activity of the different solvent extracts against the test pathogens in terms of inhibition zone diameter in decreasing order was as followsChloroform extract > Petroleum ether extract > Methanol extract for T. mentagrophytes, T. rubrum and T. tonsurans.Chloroform extract > Methanol extract > Petroleum ether extract for C. albicans and T. beigelii.     

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.     

Antifungal activity of lichen compounds against dermatophytes: a review

The growth rate inhibition of dermatophytes by compounds extracted by acetone, ethanol, methanol and water derived from representatives of several lichen genera (e.g. Caloplaca, Everniastrum, Heterodermia, Hypotrachyna, Platismatia and Ramalina) were compared on the basis of a worldwide review of published research. The examined dermatophytes included Epidermophyton floccosum, Microsporum audouinii, M. canis, M. gypseum, M. nanum, Trichophyton longifusus, T. mentagrophytes, T. rubrum, T. tonsurans and T. violaceum. The influence of selected secondary lichen compounds, for example, usnic acid, on the growth rates of these dermatophytes was also reviewed. The measurement of inhibition by lichen compounds was performed by several methods, but mostly those employing disc diffusion, broth dilution and agar dilution. The fungicidal activity of water-extracted compounds from Heterodermia leucomela and Hypotrachyna cirrhata and of methanol-extracted compounds from Evernia divaricata and Ramalina pollinaria, as well as protolichesterinic and 2-hydroxy-4-methoxy-3,6-dimethylbenzoic acids, are distinguished.     

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.     

Chicory extracts from Cichorium intybus L. as potential antifungals

In this work extracts from roots of the common vegetable Cichorium intybus L., highly appreciated for its bitter taste, were studied to investigate their possible biological activity on fungi from a variety of ecological environments: some are parasites on plants (phytopathogens) or of animals and humans (zoophilic and anthropophilic dermatophytes), others live on the soil and only seldom parasitize animals (geophilic dermatophytes). The extracts were ineffective on geophilic species and on tested phytopathogens, with the exception of Pythium ultimum, whereas they inhibited the growth of zoophilic and anthropophilic dermatophytes, in particular Trichophyton tonsurans var. sulfureum, whose treatment caused morphological anomalies, here observed by scanning electron microscopy. This behaviour is discussed on the basis of the presence in the chicory extract of the two main sesquiterpene lactones, 8-deoxylactucin and 11β,13-dihydrolactucin.     

Frequency and aetiology of dermatophytosis in children age 12 and under in the state of Amazonas,Brazil

BackgroundFew scientific studies have evaluated dermatophytosis among children in the state of Amazonas or in the greater northern region of Brazil.AimsThe aim of this study was to research the frequency and aetiology of dermatophytosis in children age 12 and under, who were seen between March 1996 and November 2005 at the Mycology Laboratory of the National Institute of Amazonian Research.MethodsFor mycological diagnoses, epidermal scales and/or hairs were used. A portion of this material was treated with potassium hydroxide for direct examination, and another portion was cultivated in Mycobiotic Agar for the isolation of dermatophytes.ResultsOf the 590 samples analysed, 210 showed positive diagnoses by direct examination and cultivation. Tinea capitis (153 cases) was the most frequent type of dermatophytosis, and Trichophyton tonsurans (121 cases) was the most frequently isolated fungal agent. Tinea corporis was observed in 48 cases where the most frequently isolated fungal agent was also T. tonsurans (17 cases), and the corporal regions most affected were the face, arms and trunk. The laboratory confirmed tinea pedis in 6 cases, and the principal fungal agents isolated were Trichophyton rubrum (3) and Trichophyton mentagrophytes (3). The presence of tinea cruris was confirmed in 3 cases, and T. rubrum, T. tonsurans and Epidermophyton floccosum were isolated from these cases.ConclusionsThe children examined were primarily affected by tinea capitis, and the main fungal agent for this dermatophytosis was T. tonsurans.     

A critical survey of 1000 cases of dermatophytosis in the tel aviv area during 1970–1975

Clinical and mycological data on 1000 cases of dermatophytosis seen from 1970 to 1975 are reported. Tinea pedis was present in 44%, T. rubrum being the main causative agent; nail involvement was present in 41% of these cases. Tineainguinalis was present in 13%, 38% of them females, withT. rubrum isolated in 87% and the swimming-pool incriminated as the main source of contamination. There were various manifestations of tinea corporis in 128 patients, withT. rubrum responsible in 91%. Among the 21 cases of tinea capitis, there was one adult female with a kerion-type due toT. violaceum, 4 cases due toM. gypseum and 2 toM. canis. Tinea favosa was seen in 6 patients, all of them females and one with a spreading fungus on the soles and palms. Amonh the 10 cases with tinea barbae,T. rubrum was found in 4,T. tonsurans in 3,T. mentagrophytes in 2 andM. gypseum in one. There were widespread lesions ofT. rubrum located on large areas of the body and including the legs, arms, groins and nails, in 11 patients with other disorders, including diabetes, Cushing's syndrome and lymphoma.It was apparent that the dermatophytic flora of Israel comprises 10 dermatophytes,T. rubrum being the predominant agent of infection (in more than 80%), with a gradually increasing incidence evident. The other agents found in our survey wereT. mentagrophytes, T. violaceum, T. schoenleinii, T. tonsurans (found sporadically),E. floccosum andMicrosporum spp.M. canis andM. gypseum, the latter being reported for the first time in this country.T. verruccosum andT. megnini, mentioned in former publications, were not found in this survey.     

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.     

Some data on the occurrence of trichophyton tonsurans in Romania

Summary During the last 12 years,T. tonsurans has been isolated from 250 cases of various mycotic infections, 80% in the adults, the rest in children. The age of infected patients varied from 1 to 66 years, the female being represented by 10%.Most of the cases (93%) involved the hair follicles, 45 of them affecting the bearded area, in which 4 clinical types could be distinguished: the superficial form, the kerion type (in 11% of the cases) and 2 intermediate forms.In 16% of cases,T. tonsurans attacked the scalp, simulating various nonmycotic dermatoses as impetigo, seborrheic dermatitis, tinea amiantacea etc. 5 cases of the scalp infection were found in the adults (3 of black-dot type, the other 2 of superficial tinea capitis). The same variety of clinical manifestations was observed in the glabrous skin, which this species affected in 7% of the cases. It also involved the nails in 2 cases only. T. tonsurans is in continuous decrease in Romania for the last ten years (4% of all the dermatophytes). This dermatophyte remained, till now, the main agent of tinea barbae in Romania. Community epidemics as those caused byM. audouinii andM. ferrugineum have not yet occurred in this country.     

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     

II. Evidence of the presence in yeast extract of substances which stimulate the growth of Histoplasma capsulatum and blastomyces dermatitidis similarly to that found in starling manure extract

Summary A medium consisting of agar plus yeast extract contained the necessary metabolites for rapid growth and sporulation ofHistoplasma capsulatum andBlastomyces dermatitidis. H. capsulatum when harvested after 10 or 30 days incubation period from this medium was shown to have a similar number of spores as well as total particle viability for each period of growth.The growth characteristics ofH. capsulatum and four different isolates ofB. dermatitidis on yeast extract medium were similar to that obtained previously using starling (Sturnis vulgaris) manure extract medium. These characteristics are rapid growth consisting of many viable spores and a low ratio of vegetative mycelium.Several isolations ofH. capsulatum from naturally contaminated soil specimens were made using yeast extract medium.From the Communicable Disease Center, Public Health Service, U. S. Department of Health, Education, and Welfare.     

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.     

The character of endogenous growth regulators in the course of development in the fungus Lentinus tigrinus

The character of endogenous growth regulators in different stages of growth and development ofLentinus tigrinus was followed by means of bioassays. The methanolic extract of differently old mycelium and fruiting body was chromatographically separated and tested for auxins by means of Avena coleoptile segments, for gibberellins by using lettuce seedlings and for cytokinins by measuring the content of chlorophyl in leaf segments of barley. Auxins were found only in young vegetative mycelium and in the growing young stalk. The level of gibberellins is more significant and it reaches the highest values in the vegetative mycelium, in the growing young stalk and in the differentiated cap. The content of auxin and gibberellin substances did not increase even in the medium after cultivation of mycelium. Bioassays of cytokinins show a slight stimulation in the vegetative mycelium and in the primordia of caps. Significant inhibition was ascertained in the fully developed stalk. The high quantities of cytokinins were found in caps when basidiospores were formed. The results show a close connection of endogenous growth substances with the growth and the development of the fungus and indicate their participation in differentiation processes.     

Effect of volatile substances fromOriganum majorana andOcimum basilicum on spore respiration and germination of some soil fungi

Oxygen uptake by the spores ofFusarium moniliforme, F. oxysporum, F. semitectum, F. solani, Mucor racemosus andTrichoderma viride was increased in the presence of volatile substances extracted, fromOriganum majorana andOcimum basilicum. This increase was greater in the presence of volatile substances fromO. basilicum thanO. majorana, except in the case ofF. semitectum where the reverse was true. A drop in the RQ of all the germinating spores was observed in the presence of these substances. Volatile substances fromO. majorana reduced the spore germination ofM. racemosus whereas the spores ofT. viride were stimulated to germinate. Volatile substances fromO. basilicum stimulated the spore germination ofM. racemosus whereasT. viride spores were not affected.     

Induction of antimicrobial compounds in alfalfa callus by cell wall components fromFusarium oxysporum

Callus cultures ofMedicago sativa were treated with a preparation of elicitor from the mycelium ofFusarium oxysporum. The ability of the elicitors to induce the formation of antimicrobial substances was tested biologically. The preparation of the cell walls ofF. oxysporum induced the occurrence of substances with a strong antimicrobial effect. Thermal sterilization had no effect on the activity of the elicitor.     

Experience with studying suspension media in actinomycete lyophilization]

Viability, cultural features and antibiotic-production properties of the organisms producing tetracycline, chlortetracycline, erythromycin, neomycin, oxytetracycline and polymyxin were studied after their storage for 2 years in ampoules at a temperature of 4--10 degrees in lyophilized state with the use of sodium glutamate, polyvinylpyrrolidone, their combination and horse serum. The highest growth rate was observed in most of the cultures lyophilized in sodium glutamate. The growth of the cultures lyophilized in the solution of polyvinylpyrrolidone alone was mainly scanty or moderate. The antibiotic production level in some strains lyophilized in sodium glutamate or its combination with polyvinylpyrrolidone was after storage for 2 years somewhat higher than that in the control. The cultural features, i.e. the colour of the aerial and substrate mycelium and pigment secretion did not significantly differ in the lyophilized cultures and the cultures maintained on agarized media.     

Trichophyton rubrum (Castellani) var. flava,var. nova a yellow pigment forming Trichophyton rubrum

Summary and Conclusions A hitherto unknown variant ofT. rubrum var.flava is described which besides its yellow pigment has the following characteristics different fromT. rubrum (Castellani). A much slower growth and a smaller diameter of the giant culture and an appreciable difference in the light absorption curve of the extracted pigment.     

Rapid detection ofRhizoctonia species, causal agents of rice sheath diseases, by PCR-RFLP analysis using an alkaline DNA extraction method

Restriction fragment length polymorphism (RFLP) analysis for DNA products amplified by the polymerase chain reaction (PCR) was used for the direct detection ofRhizoctonia solani AG 1 IA and AG 2-2 IIIB,R. oryzae, R. oryzae-sativae andR. fumigata from the diseased rice sheaths. A rapid DNA extraction method with a solution of sodium hydroxide was conducted to extract parasite DNA from diseased rice sheaths. 28S ribosomal DNA (rDNA) derived from fungal genomic DNA extracted by the alkaline method was specifically PCR-amplified. The results of PCR-RFLP analysis for DNA samples from artificially inoculated rice sheath tissues with eachRhizoctonia spp. and the corresponding culture on the medium using two restriction enzymes.HhaI andMspI, showed identical polymorphisms. PCR-RFLP analysis using DNA samples from naturally infected rice sheath tissues also revealed the possibility of direct diagnosis ofR. solani AG 1 IA,R. oryzae andR. oryzae-sativae.