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PubMed2005

Non-dermatophytic molds as agents of onychomycosis in Izmir, Turkey - a prospective study.

The purpose of this study was to determine the prevalence of causative non-dermatophytic filamentous fungi in onychomycosis. Totally 1,222 (1,222 x 3 = 3,666) samples of nail scrapings from 1,146 patients (from 76 patients two specimens: both from finger- and toe-nails) with prediagnosis of onychomycosis sent to the Mycology Laboratory from the Clinic of Dermatology, Ege University Hospital, Izmir, Turkey, July 2001-December 2003, were prospectively studied with conventional mycological procedures. The set criteria for the diagnosis of onychomycosis due to non-dermatophytic molds were: (1) Observation of fungal elements in 15% KOH-preparations made from nail scrapings, (2) growth of the same mold in all three consecutive cultures of the specimens taken three times from the same patient with one-week intervals, (3) no growth of a dermatophyte or yeast in three consecutive cultures. As agents of onychomycosis molds were detected in 33 (9%), dermatophytes in 175 (48%), yeasts in 150 (41%), and mixed (two different fungi) in 8 (2%) patients. In cases of mold onychomycosis, 11 (33%) had finger-nail and 22 (67%) toe-nail infection; 25 (76%) were female and 8 (24%) male; and 27 (82%) were above 40 years of age. The agents of mold onychomycosis, in order of frequency, were Aspergillus niger (7), Acremonium spp. (6), Fusarium spp. (6), Ulocladium spp. (4), sterile mycelia (2), Alternaria sp. (1), Aspergillus flavus (1), Aspergillus fumigatus (1), Aspergillus terreus (1), Cladosporium sp. (1), Paecilomyces spp. (1), Scopulariopsis sp. (1) and Trichoderma sp. (1). In conclusion, this study showed that non-dermatophytic molds were responsible for nearly 10% of onychomycoses cases attending the dermatology outpatient clinic of a university hospital in Izmir, Turkey. Since molds are common contaminants in the laboratory, cultures from consecutively taken nail scrapings should be made and carefully evaluated in order to diagnose a "mold onychomycosis".

Acremonium↗

PubMed1991

Plants used in Guatemala for the treatment of dermatophytic infections. 1. Screening for antimycotic activity of 44 plant extracts.

Skin infections are common diseases in developing countries, of which dermatophytoses are of particular concern in the tropics, especially in infants. Through ethnobotanical surveys and literature review 100 plants were detected as being used in Guatemala for the treatment of dermatophytoses. Of these, 44 plants were screened for in vitro activity against the most common dermatophytes (Epidermophyton floccosum, Microsporum canis, Microsporum gypseum, Trichophyton mentagrophytes and Trichophyton rubrum). Results showed that aqueous extracts from 22 of the plants tested inhibit one or more of the dermatophytes. The most commonly inhibited dermatophytes were E. floccosum (43.2%), T. rubrum (36.0%), and T. mentagrophytes (31.8%); the less inhibited were M. canis (22.7%) and M. gypseum (24.0%). Plants of American origin which exhibited anti-dermatophyte activity were: Byrsonima crassifolia, Cassia grandis, Cassia occidentalis, Diphysa carthagenensis, Gliricidia sepium, Piscidia piscipula, Sambucus mexicana, Smilax regelii, Solanum americanum and Solanum nigrescens. Fungicidal and fungistatic activities as well as the minimal inhibitory concentration were demonstrated. These results provide a scientific basis for the use of these plants for the treatment of dermatophyte infections in man.

Antifungal Agents↗

PubMed1993

Immune response and host resistance of humans to dermatophyte infection.

Clearing of dermatophyte infection depends on a cell-mediated immune response. Antibodies to fungi, although present in infected persons, are ineffective at ridding the skin of fungi. Experiments in which human volunteers were deliberately infected with dermatophytes identified two major groups on the basis of cellular immune responsiveness: (1) those who mount decisive delayed-type hypersensitivity that results in clearing of the infection, and (2) those who have absent or defective cellular immunity that prevents them from mounting an effective response to dermatophytes and thus predisposes them to chronic or recurrent dermatophyte infection. The courses of experimental infection in these two groups were compared with skin test results. The presence of an acute inflammatory infection was correlated with delayed-type (T-cell-mediated) hypersensitivity to a trichophytin skin test and the ability of persons affected in this manner to achieve mycologic cure. In contrast, chronic infection was associated with high immediate (anti-Trichophyton-IgE-mediated) hypersensitivity and low or waning delayed-type (T-cell-mediated) hypersensitivity to trichophytin. Despite this immune deficiency, these persons had a normal response to other infectious agents and skin test antigens. This type of selective and perhaps induced immune deficit may be relatively common, because persons chronically infected with a dermatophyte constitute 10% to 20% of the general population.

Chronic Disease↗

PubMed1993

Suppression of immunity and inflammation by products produced by dermatophytes.

When normal, previously uninfected hosts are exposed to dermatophytes under experimental occlusive conditions, infections develop and cell-mediated immunity is induced. Subsequent exposure to dermatophytes under the same conditions elicits an immune response that is capable of curing the infection, once occlusion is removed. Lymphocytes or monocytes involved in the immune response may produce cytokine growth factors that foster stratum corneum turnover and shedding of the fungus from the skin surface. Chronic dermatophyte infections develop when conditions of the local environment or virulence factors of the fungus outweigh the capabilities of cell-mediated immunity, or when a person does not develop cell-mediated immunity to fungal antigens. Even if immunity does develop, certain dermatophytes such as Trichophyton rubrum produce substances that diminish the immune response. One class of these substances, the mannans, can indirectly inhibit stratum corneum turnover. A nonresponsive host immune system or the suppression of the immune response by products produced by dermatophytes can prevent complete eradication of the fungus or predispose to reinfection.

Antifungal Agents↗

PubMed2003

Epidemiology of dermatophyte infection in Auckland, New Zealand.

This report describes the epidemiology of culture-proven dermatophyte infection in Auckland, New Zealand. The authors undertook a retrospective review of laboratory data for the period from June 1999 to July 2002. There were 10 004 dermatophyte isolates. The most common isolates were Trichophyton rubrum (69%) and Trichophyton mentagrophytes (19%). Microsporum canis was mainly isolated from children. The prevalence of T. mentagrophytes increased with patient age (P < 0.001). Trichophyton rubrum was most common in those aged between 20 and 59 years. The incidence of culture-proven dermatophyte infection was 2.9/1000 population for the year 2000, and the incidence increased with patient age (P < 0.001). It is concluded that dermatophytes causing superficial mycoses in the Auckland region are essentially similar to Australia and other Western countries, although some new organisms are seen as a result of the migration of people from other countries. The incidence of local dermatophyte infection increases with age.

Adolescent↗

PubMed2002

PCR identification of dermatophyte fungi Trichophyton rubrum, T. soudanense and T. gourvilii.

Diagnosis of dermatophytosis employing conventional laboratory procedures has been complicated by the slow growth and varied morphological features shown by dermatophytes. After analysis of the nucleotide base sequences of a 1.2-kb fragment amplified from a dermatophyte fungus Trichophyton rubrum by arbitrarily primed PCR with random primer OPD18, a pair of primers (TRIF and TR1R) was designed and evaluated for specific identification of T. rubrum. The sensitivity of the primers TR1F and TR1R was high, as a specific PCR band of c. 600 bp was detected from as little as 7 pg of T. rubrum DNA. By examining 92 dermatophyte strains and clinical isolates, it was found that this pair of primers reacted in PCR with T. rubrum, T. soudanense and T. gourvilii through formation of the specific fragment of 600 bp, but not with any other of the dermatophyte species or varieties, fungi, yeasts or bacteria tested. As T rubrum is one of the most frequently isolated dermatophyte fungi, and T. soudanense and T. gourvilii are relatively uncommon in many parts of the world, these primers can be used for rapid, sensitive and specific identification and differentiation of T. rubrum from other fungi and micro-organisms.

DNA, Fungal↗

PubMed2005

Culturing dermatophytes rapidly from each toe web by fingertip.

The diagnosis of tinea pedis is usually confirmed by microscopy and culture of skin scrapings. Isolating dermatophytes by fungal culture gives more reliable proof of infection and has the advantage of identifying the causative organisms. Nevertheless, culture examination is complementary to microscopy and is not routinely performed because it is time- and cost-consuming. Herein, we propose a new culturing method, the 'finger-sampling method', for collecting dermatophytes from patients' toe webs using the examiner's fingertip as a sample collection tool. Using this method, four toe webs of a foot can be examined at one time on one culture dish. Every toe web of 50 patients with untreated tinea pedis were examined, and dermatophytes were grown from 83 out of 107 (78%) KOH positive toe webs. The isolation ratio by the finger-sampling method was comparable to that by traditional slant culture of skin scrapings performed by skilled practitioners. Culture results were also positive in 19 out of 53 (36%) diseased but KOH negative toe webs and in 38 (16%) normal toe webs, suggesting the existence of unidentified infection. Additionally, we confirmed the efficacy of this method for detecting dermatophyte attachment on the healthy toe web skin of volunteers who had just been exposed to contaminated areas, i.e. Japanese public baths or a bath mat stepped on by a patient disseminating dermatophyte propagules.

Adolescent↗

PubMedDate not supplied

Dermatophytes from cases of skin disease in cats and dogs in Turin, Italy.

In urban environments, pet animals such as dogs and cats may be largely responsible for the progressive increase of zoophilic over anthropophilic dermatophytes in the aetiology of human dermatophytoses. Mapping, in each city, of the natural foci of zoophilic dermatophytes may thus be important for understanding the epidemiology of human dermatophytoses, and for planning preventive measures. We have surveyed dogs and cats suspected of carrying dermatophytic lesions in the Turin area. Hairs, skin scrapings and the contents of pustules or vesicles were inoculated on Dermasel agar supplemented with choramphenicol and cycloheximide. The mating type of the isolates was checked, testing their compatibility with the two mating types of Arthroderma simii Stockdale, Mackenzie and Austwick. We isolated dermatophytes from about 40% of the cases examined. Microsporum canis Bodin was the only dermatophyte found in the lesions. In the cats the lesions were more frequent, in the dogs more severe. Animals less than a year old and male dogs were most often affected. Some cases of transmission of the infection between animals and from animals to man are described. All the isolates of M. canis, tested for mating behaviour, were non-reactive.

Age Factors↗

PubMedDate not supplied

Isolation of dermatophytes from house dust on a medium containing gentamicin and flucytosine.

Dermatophytes are usually isolated from house dust by using actidione-chloramphenicol Sabouraud glucose medium (ACS medium). We have prepared a new medium, 5FC medium, by adding gentamicin sulphate (GS) and 5-fluorocytosine (5FC) to ACS medium to achieve more efficient isolation of dermatophytes from house dust. 5FC medium was more effective in isolating dermatophytes than ACS medium or ACS medium supplemented with GS alone. Trichophyton rubrum could be grown from 13 out of 19 house dust samples from the homes of patients with tinea pedis (68.4%), and T. mentagrophytes could be grown from 17 out of 21 (81.0%). Two of 20 house dust samples from the home of a control family without dermatophytosis grew only one colony of dermatophytes in 5FC medium; the rest of the samples showed no growth. The number of colonies isolated on 5FC medium was much higher than on ACS medium (5.3 vs. 2.0 for T. rubrum and 17.2 vs. 2.1 for T. mentagrophytes). In addition, the size of the isolated colonies was much larger than that on ACS medium. Thus, 5FC medium can be regarded as a useful tool for isolating dermatophytes from various contaminated samples.

Anti-Bacterial Agents↗

PubMed2005

Antifungal activity of Ocimum gratissimum towards dermatophytes.

The development of more effective and less toxic antifungal agents is required for the treatment of dermatophytosis. Plants and their preparations have been used as medicines against infectious diseases. Extracts of Ocimum gratissimum leaves were investigated for in vitro antifungal activity, using agar dilution technique against dermatophytes. The extracts (hexane, chloroform fractions, the essential oil and eugenol) produced antifungal activities against Microsporum canis, M. gypseum, Trichophyton rubrum and T. mentagrophytes. Trichophyton rubrum, the most common aetiological agent of dermatophytosis in Goiânia, state of Goiás, Brazil, was also the most susceptible dermatophyte. The hexane fraction and eugenol were the most active. Hexane fraction inhibited the growth of 100% of dermatophytes at a concentration of 125 microg ml(-1), while eugenol inhibited the growth of 80% of dermatophytes at this same concentration. These results show that extracts of O. gratissimum are active in vitro against human pathogenic dermatophytes.

Antifungal Agents↗

PubMed2005

Dermatophyte infections in the Ljubljana region, Slovenia, 1995-2002.

We studied dermatophyte infections in patients, examined in the Mycological Laboratory of the Department of Dermatology, University Medical Centre Ljubljana during the period 1995-2002. A total of 42,494 samples were collected from 33,974 patients suspected to have dermatomycosis. Dermatophytes were identified in 8286 (71.2%) positive cultures. Microsporum canis was the most frequent dermatophyte isolated (46.8%), followed by Trichophyton rubrum (36.7%), T. mentagrophytes var. interdigitale (7.9%) and T. mentagrophytes var. mentagrophytes (4.9%). Less frequently isolated were M. gypseum, T. verrucosum, Epidermophyton floccosum, T. tonsurans and T. violaceum. The most common dermatophyte infections included tinea corporis, onychomycosis, tinea pedis and tinea faciei. Zoophilic dermatophytes were most commonly recovered from children and adolescents with tinea capitis, tinea corporis and tinea faciei. Anthropophilic species were identified mostly in adults with tinea pedis, onychomycosis and tinea inguinalis. During the period studied, we recorded a decline in the rate of M. canis infections, while infections produced by T. rubrum increased in frequency.

Adolescent↗

PubMed2005

Survey of dermatophytes on clinically normal cats in the southeast of England.

OBJECTIVES: To report the incidence of dermatophytes on the hair coat of asymptomatic cats in the southeast of England. Asymptomatic cats are often blamed for transmission of dermatophytes between animals and humans. This study may help to clarify whether cats are responsible for the increase in fungal infections among the human population. METHODS: A total of 169 clinically healthy cats without any dermatological signs were sampled using the Mackenzie brush technique and cultured for dermatophytes. Thirty cats were from a closed colony and 139 were feral or from domestic households in the southeast of England. RESULTS: The incidence of Microsporum canis and Trichophyton mentagrophytes in household and feral cats was 2.16 per cent for each dermatophyte. This survey shows little difference in the isolation rates of M. canis between the southeast and southwest of England, which was reported on in 1994. CLINICAL SIGNIFICANCE: Given the low number of dermatophytes isolated, asymptomatic cats are unlikely to be responsible for the increasing incidence of human infection. Asymptomatic carriers with T. mentagrophytes in the hair coat have not been previously reported and may need to be considered when treating humans with trichophytosis.

Animals↗

PubMed1977

Dermatophyte isolation media: quantitative appraisal using skin scales infected with Trichophyton mentagrophytes and Trichophyton rubrum.

Various dermatophyte isolation media were quantitatively appraised by colony counts for their ability to support growth when suspensions of trypsin-treated infected-skin scales were used as inocula. Evaluation included guinea pig skin scales infected with a granular Trichophyton mentagrophyton mentagrophytes, and one trial was conducted using human skin scales infected with Trichophyton rubrum. No differences in the ability to support growth were observed among Taplin Dermatophyte Test medium, Dermatophyte Test Medium (Schering Diagnostics, Port Reading, N.J.),Sabouraud medium plus cycloheximide and chloramphenicol, Youssef medium for dermatophytes product no. 103S semisynthetic lots no. 106 and no. 107. With skin scales not grossly contaminated with bacteria, similar counts were obtained with Littman oxgall agar without antibiotics. Youssef medium for dermatophytes product no. 103N natural lot no. 109 was significantly different from the other media in that lower counts were obtained.

Animals↗

PubMed1998

Tinea capitis dermatophytes: susceptibility to antifungal drugs tested in vitro and in vivo.

BACKGROUND: Tinea capitis is a worldwide-spread infection of the scalp caused by dermatophytes and is predominantly seen in children. The clinical manifestations range from mild scaling lesions to widespread alopecia or highly inflammatory suppurating lesions. Terbinafine and itraconazole seem to be promising therapies with shorter treatment durations than griseofulvin. OBJECTIVE: The objective of the present study was to test the sensitivity of different species of dermatophytes towards terbinafine and itraconazole, and to compare the results with a retrospective study on 35 immunocompetent patients with tinea capitis who were treated with terbinafine (Lamisil(R)). METHODS: Minimal inhibitory concentrations (MIC) were measured with an agar dilution method. RESULTS: Each tested species of dermatophyte was sensitive to terbinafine and itraconazole at different concentration ranges. The MIC for terbinafine ranged from 0.005 to 0.5 microg/ml and for itraconazole from 40 to 80 microg/ml. Microsporum canis was the dermatophyte least sensitive to terbinafine. Our retrospective study showed that the cure rate was excellent for Trichophyton violaceum and T. soudanense, variable for T. mentagrophytes and poor for M. canis and M. langeronii. CONCLUSIONS: (i) Regarding the results of susceptibility tests obtained with species involved in tinea capitis, clinical efficacy is not related to MIC measured in vitro; (ii) identification of the isolated dermatophyte from tinea capitis seems to be important for choosing the appropriate treatment.

Antifungal Agents↗

PubMed2004

[Chitin synthase (CHS) gene analysis of dermatophytes].

About 620-bp genomic DNA fragments of CHS1 genes were amplified from 13 species of dermatophytes by polymerase chain reaction (PCR) and sequenced. The phylogenetic analysis of CHS1 gene fragments of these dermatophyte species revealed that 3 genera of Epidermophyton, Microsporum and Trichophyton were genetically different from each other. The molecular analysis of CHS1 genes will provide useful information for the identification of dermatophytes. The species-specific primers were designed from the nucleotide sequences of CHS1 gene in 3 teleomorphs of T. mentagrophytes. Using these primers the PCR analysis identified the clinical isolates of T. mentagrophytes from rabbit as A. benhamiae. By PCR analysis with the dermatophyte specific primer pair, dermatophyte DNA could be diagnosed directly and rapidly in clinical skin samples. The full length of CHS1 and CHS2 genes of Arthroderma benhamiae (one of the teleomorphs of T. mentagrophytes) was sequenced by 5'-RACE and 3'-RACE methods using cDNA as a template. The full length cDNA sequences of CHS1 gene (3158bp) and CHS2 gene (3392bp) were proved to encode 890 and 419 amino acids, respectively. The amino acid sequences of A. benhamiae CHS1 and CHS2 in the conserved regions shared, respectively, about 70% and 80% sequence similarity with those of the other filamentous ascomycetes registered in the data base of the GeneBank. RT-PCR analysis suggested that chitin synthase inhibitors (nikkomycin Z and polyoxin D) might stimulate the expression of CHS1 mRNA in A. benhamiae, and not the expression of CHS2 mRNA.

Arthrodermataceae↗

PubMed2005

In vitro activity of Phytolacca dodecandra (Endod) against dermatophytes.

There is a need for better and less costly treatment of superficial mycotic infections, and one approach might be testing of'traditionally used plants for their antifungal activities as potentials for drug development. The aim of the present study was to determine the in vitro activity of Phytolacca dodecandra (Endod) on various species of dermatophytes and yeasts of medical importance. The aqueous extract from the plant P. dodecandra was tested for its antifungal activity against 33 dermatophyte and yeast strains. The minimum inhibitory concentration (MIC) was determined by adopting the broth microdilution method for testing of conidium forming filamentous fungi according to the NCCLS M38-P proposed standard with some modifications. The MIC of P. dodecandra against the dermatophytes tested ranged from 19.5 mg/l to 156.0 mg/l, while for all the yeasts the MIC was >500 mg/l. The minimum inhibitory concentration for 50% (MIC50) of the dermatophyte strains was 62.5 mg/l. The extract showed fungicidal activity against the dermatophytes that ranged from 19.5 to 312.5 mg/l. No activity was observed against the yeasts. From our preliminary results antifungal activity of P. dodecandra has been shown. This should he strengthened with more extensive studies which address both the antifungal activity and the active principle that is responsible for its fungicidal activity.

Antifungal Agents↗

PubMed1989

[Dermatophytes in clinically healthy dogs and cats].

The hair and skin of 300 clinically healthy animals, 268 dogs and 32 cats, were examined mycologically. The method described by Mariat and Tapia (1966) was used for the examination, along with square pieces of the fitted carpet Kovral. The dermatophytes were isolated in 12 samples, all from the material taken from dogs. Trichophyton mentagrophytes was isolated six times, Microsporum canis four times, Trichophyton gallinae once, Trichophyton rubrum once. The origin of the dermatophyte Trichophyton gallinae, found in a village dog, was not determined. In one case of occurrence of the dermatophyte Trichophyton mentagrophytes in a dog the dermatophyte was probably transmitted from man to the dog. Microsporum canis was not proved to be the most frequent dermatophyte in dogs or cats in this country.

Animals↗

PubMed1977

[Moder classification of dermatophytes].

Dermatophytes are classified according to two systems. The first, or parasitic classifications of Sabouraud, rests on the morphology of the dermatophytes on the hair in vivo (Achorion, Trichophyton endothrix or ectothrix microides and megaspores, Microsporum) or on the absence of growth on the hair in vivo (Epidermophyton). In the second type they are classified according to their saprophytic morphology. There are many classification of this type based on the asexual state of the dermatophytes, e.g. the classification of Emmons (Trichophyton, Microsporum, Epidermophyton) or the classification of Vanbreuseghem and De Vroey (Microides, Trichophyton, Microsporum, Epidermophyton, Keratinomyces). As the existence of a sexual state of the dermatophytes has been demonstrated, the dermatophytes are also classified in two perfect genera: Arthroderma and Nannizzia. In this paper it is assumed that both classification have to be used because they are not correlated.

Arthrodermataceae↗