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PubMed1989

Dermatophyte onychomycosis in children.

Four-hundred and ninety-four schoolchildren and 200 children attending a paediatric medical out-patient clinic were screened for clinical evidence of dermatophyte onychomycosis. Only one case was found and mycological investigation showed this to be due to Trichophyton rubrum. The overall prevalence of dermatophyte onychomycosis in the prospective survey of schoolchildren was 0.2%, confirming that this type of infection is very uncommon in children. Seven further cases of nail infection occurring in children under the age of 12 years are reported. These represent all cases collected by our laboratory over a 3-year period. In six cases where culture of nail was positive, the causative organism was T. rubrum. In four cases at least one parent was also found to have dermatophyte onychomycosis; again, T. rubrum was the causative organism in all cases. Dermatophyte onychomycosis in children appears to be of low infectivity, (in contrast to viral wart infection), and a parental source should be suspected and sought.

Adolescent↗

PubMed2006

Kerion and dermatophytic granuloma. Mycological and histopathological findings in 19 children with inflammatory tinea capitis of the scalp.

BACKGROUND: Inflammatory tinea capitis or kerion is the result of a hypersensitivity reaction to a dermatophytic infection. Majocchi's granuloma, in contrast, usually begins as a suppurative folliculitis and culminates in a granulomatous reaction. OBJECTIVES: To present clinical, mycological and histopathological findings for 19 cases of kerion of the scalp in children. METHODS: Nineteen children were investigated (14 boys and five girls) with a mean age of 6.5 years. A potassium hydroxide (KOH) exam and culture in Sabouraud dextrose agar were performed, followed by a biopsy with hematoxylin and eosin, periodic acid-schiff (PAS) and Gomori-Grocott stains. The same investigations were carried out in four control cases of noninflammatory tinea capitis. RESULTS: Clinical history varied from 2 to 16 weeks (mean 6.6 weeks). Diagnosis was confirmed by a positive KOH exam: all cases except one had a positive culture. The following dermatophytes were isolated: Microsporum canis (32%), Trichophyton mentagrophytes (27%), Trichophyton tonsurans (21%), Trichophyton rubrum (10%) and Microsporum gypseum (5%). The histopathological findings were: suppurative folliculitis (SF) 11%, SF plus suppurative dermatitis 37%, suppurative and granulomatous dermatitis (SGD) 26% and SGD plus fibrosing dermatitis 26%. Fungi were observed in 63% of the histopathological sections. Perifollicular infiltrates (PF) around the parasitized hair follicles were identified in the four noninflammatory control cases due to M. canis. CONCLUSIONS: Kerion Celsi is an inflammatory or suppurative type of tinea capitis caused by zoophylic dermatophytes (M. canis and T. mentagrophytes), but also by antrophophylic (T. tonsurans and T. rubrum) and geophylic (M. gypseum) dermatophytes. Histopathological findings showed a spectrum from mild suppurative folliculitis to dense granulomatous infiltrates without a clear relationship with the clinical features.

Biopsy↗

PubMed1997

Phylogenetic analysis of 8 dermatophyte species using chitin synthase 1 gene sequences.

Nucleotide sequences of chitin synthase 1 (CHS1) gene of eight species of dermatophytes, Arthroderma benhamiae, A. fulvum, A. grubyi, A. gypseum, A. incurvatum, A. otae, A. simii and A. vanbreuseghemii were obtained and analysed for their phylogenetic relationship. A 600-bp genomic DNA fragment of the CHS1 gene was amplified from these dermatophytes by polymerase chain reaction (PCR) and sequenced. The CHS1 nucleotide sequences of these eight dermatophyte species showed more than 85% similarity between the species. The phylogenetic analysis of their sequences revealed three clusters, the first cluster consisting of A. benhamiae, A. simii and A. vanbreuseghemii, the second cluster consisting of A. fulvum, A. gypseum and A. incurvatum, and the third cluster consisting of A. grubyi and A. otae. The phylogenetic analysis of CHS1 gene in this study will provide useful information for classification and understanding the evolution of these dermatophyte species.

Arthrodermataceae↗

PubMed2006

[Trichophyton eboreum--a recently described dermatophyte].

BACKGROUND: The distribution of distinct species of dermatophytes is continuously changing and different species of dermatophytes can cause the same type of tinea. Therefore, it is necessary to always identify the pathogenic agents in dermatophytoses. PATIENTS AND METHODS: An unusual fungus was isolated from moccasin type tinea pedis in a HIV-positive immunocompromised patient from the Ivory Coast and characterized by morphological, physiological and genetic methods. RESULTS: The strain under study showed typical characteristics of dermatophytes but considering all its morphologic, physiologic and genetic features it unambiguously differed from all previously described species. CONCLUSION: The strain was recently described as a new dermatophyte species (Trichophyton eboreum). Distribution and pathogenicity of this species are as yet unknown.

Humans↗

PubMed1995

The dermatophytes.

The etiologic agents of the dermatophytoses (ringworm) are classified in three anamorphic (asexual or imperfect) genera, Epidermophyton, Microsporum, and Trichophyton. Species capable of reproducing sexually belong in the teleomorphic genus, Arthroderma, of the Ascomycota. On the basis of primary habitat association, they may be grouped as geophilic (soil associated), zoophilic, and anthropophilic. Adaptation to growth on humans by most geophilic species resulted in diminished loss of sporulation, sexuality, and other soil-associated characteristics. The dermatophytes have the ability to invade keratinized tissue (skin, hair, and nails) but are usually restricted to the nonliving cornified layer of the epidermis because of their inability to penetrate viable tissue of an immunocompetent host. However, invasion does elicit a host response ranging from mild to severe. Acid proteinases, elastase, keratinases, and other proteinases reportedly act as virulence factors. The development of cell-mediated immunity correlated with delayed hypersensitivity and an inflammatory response is associated with clinical cure, whereas the lack of or a defective cell-mediated immunity predisposes the host to chronic or recurrent dermatophyte infection. Chronic dermatophytosis is mostly caused by Trichophyton rubrum, and there is some evidence that mannan produced by this fungus suppresses or diminishes the inflammatory response. Since dermatophytes cause a communicable disease, modes of transmission and control are discussed as well as a survey of recent trends in therapy. Collection of specimens, culture media, and tests for identification are also presented. Genetic studies have led to an understanding of incompatibility mechanisms, pleomorphism and variation, resistance to griseofulvin, and virulence. Molecular biology has contributed to our knowledge of the taxonomy and phylogenetic relationships of dermatophytes.

Antigens, Fungal↗

PubMed1965

ANTIBIOTIC ACTION OF GRISEOFULVIN ON DERMATOPHYTES.

El-Nakeeb, Moustafa A. (Rutgers, The State University, New Brunswick, N.J.), W. L. McLellan, Jr., and J. O. Lampen. Antibiotic action of griseofulvin on dermatophytes. J. Bacteriol. 89:557-563. 1965.-The concentrations of griseofulvin required to inhibit growth and to produce the characteristic morphological distortions were determined for dermatophytes (highly sensitive), fungal plant pathogens (moderately sensitive), filamentous nonpathogenic fungi (poorly sensitive), and for yeasts and Escherichia coli (insensitive). Addition of griseofulvin to small inocula of the dermatophytes Microsporum gypseum and Trichophyton mentagrophytes produced complete and apparently permanent growth inhibition. If the antibiotic was added to actively growing cultures, the inhibition was only temporary, even with the most sensitive dermatophytes. During growth inhibition, griseofulvin temporarily halted the net synthesis of protein and nucleic acids, and of the amino acid and nucleotide pools. It decreased substantially the incorporation of C(14)-uridine or C(14)-thymidine into nucleic acids of M. gypseum, but not that of C(14)-leucine or C(14)-valine into protein. With a less sensitive culture, T. mentagrophytes x8, the uptake of uridine was inhibited only to a slight extent; the incorporation of leucine was unaffected. A partial protective effect of pruine nucleotides against growth inhibition by griseofulvin was observed with one strain of T. mentagrophytes, but not with another strain or with M. gypseum.

Amino Acids↗

PubMed1999

Species identification and strain differentiation of dermatophyte fungi by analysis of ribosomal-DNA intergenic spacer regions.

Restriction fragment length polymorphisms (RFLPs) identified in the ribosomal-DNA (rDNA) repeat were used for molecular strain differentiation of the dermatophyte fungus Trichophyton rubrum. The polymorphisms were detected by hybridization of EcoRI-digested T. rubrum genomic DNAs with a probe amplified from the small-subunit (18S) rDNA and adjacent internal transcribed spacer (ITS) regions. The rDNA RFLPs mapped to the nontranscribed spacer (NTS) region of the rDNA repeat and appeared similar to those caused by short repetitive sequences in the intergenic spacers of other fungi. Fourteen individual RFLP patterns (DNA types A to N) were recognized among 50 random clinical isolates of T. rubrum. A majority of strains (19 of 50 [38%]) were characterized by one RFLP pattern (DNA type A), and four types (DNA types A to D) accounted for 78% (39 of 50) of all strains. The remaining types (DNA types E to N) were represented by one or two isolates only. A rapid and simple method was also developed for molecular species identification of dermatophyte fungi. The contiguous ITS and 5.8S rDNA regions were amplified from 17 common dermatophyte species by using the universal primers ITS 1 and ITS 4. Digestion of the amplified ITS products with the restriction endonuclease MvaI produced unique and easily identifiable fragment patterns for a majority of species. However, some closely related taxon pairs, such as T. rubrum-T. soudanense and T. quinkeanum-T. schoenlenii could not be distinguished. We conclude that RFLP analysis of the NTS and ITS intergenic regions of the rDNA repeat is a valuable technique both for molecular strain differentiation of T. rubrum and for species identification of common dermatophyte fungi.

Arthrodermataceae↗

PubMed2004

Clinical benefit of recovering dermatophytes from skin swabs sent for bacterial culture.

We incubated Sabouraud dextrose agar plates to recover dermatophytes from skin swabs sent for bacterial culture. Dermatophytes were recovered from 66 (0.3%) of 22,613 cultures. Twenty-one patients received specific antifungal treatment when their dermatophyte was reported. Most clinicians thought recovering and reporting the dermatophyte contributed to patient management.

Adolescent↗

PubMed2006

A study on tinea gladiatorum in young wrestlers and dermatophyte contamination of wrestling mats from Sari, Iran.

OBJECTIVE: To study the prevalence of tinea gladiatorum among young wrestlers and dermatophyte contamination of wrestling mats from Sari city, the capital of Mazandaran, a northern province of Iran. DESIGN: 324 wrestlers (aged 9-20 years) from 7 active clubs in Sari city were examined, and skin scrapings were obtained from 135 wrestlers suspected of having tinea gladiatorum. The scraped skin samples were evaluated with potassium hydroxide. Pleated carpet sterile fragments (5 x 5 cm) were used for to survey of wrestling mat contamination. Sabouraud's dextrose agar with and without chloramphenicole and cyclohexamide was used to culture scrapings and wrestling mat samples. The dermatophytes were identified by routine laboratory techniques. RESULTS: Our study showed that of the 324 wrestlers, 65 (20.1%) had tinea gladiatorum. Most lesions were on the trunk and head. All the wrestling mat samples were positive for dermatophytes. Trichophyton tonsurans was isolated from all the scrapings and wrestling mat samples. CONCLUSION: Considering that several colonies of T tonsurans were isolated from all the wrestling mats and from wrestlers with tinea gladiatorum (as the only dermatophyte species) we think that the contamination of wrestling mats with T tonsurans has a crucial role in the injection of wrestlers.

Adolescent↗

PubMedDate not supplied

[Occurrence of dermatophyte, in nails, feet and hands of university students].

The objective of this paper was to evaluate the occurrence of dermatophytes, specifically in the nails, feet and hands of university students with and without lesions. Two hundred and eighty samples were collected; 31 (11.1%) were positive by direct examination, while only 20 (7.1%) showed dermatophyte growth in culture, as well as direct positive examination. Trichophyton rubrum was the most frequently isolated (80%) dermatophyte followed by T. mentagrophytes (20%). Considering the sites analyzed, dermatophyte occurrence was: 10.4% in toenails, 5% in foot skin, 2.5% in fingernails and 0.4% in hand skin.

Adolescent↗

PubMedDate not supplied

Presence of keratinophilic fungi with special reference to dermatophytes on the haircoat of dogs and cats in México and Nezahualcoyotl cities.

In order to study the presence of keratinophilic fungi with special reference to dermatophytes on the coat of dogs and cats living in the cities of Mexico and Nezahualcoyotl in the Metropolitan area of Mexico City, two hundred samples were collected from dogs and one hundred from cats by using the MacKenzie's tooth brush technique, they were processed by routine mycological methods for dermatophyte fungi, results were analyzed by means of the statistical packages SAS. There were isolated 67 and 90 keratinophilic strains from cats and dogs samples, respectively. The most commonly fungi isolated in pure culture in this study were Chrysosporium spp (25%), followed by Trichophyton terrestre (22%), Microsporum gypseum (5%), M. canis (4%), as well as mixed cultures like Chrysosporium spp. & M. gypseum (2%) and T. terrestre & T. mentagrophytes (1%). Keratinophilic fungi were found in higher numbers in the cat haircoat (67%) than in the dog's (45%) and the same was true with regard to dermatophytes with 12 isolates out of a 100 samples in cats and 7 Isolates out of 200 samples from dogs. This may represent a health risk for humans in contact with a dermatophyte infected cat or dog.

Animals↗

PubMed2003

Dermatophyte infections.

Dermatophytes are fungi that require keratin for growth. These fungi can cause superficial infections of the skin, hair, and nails. Dermatophytes are spread by direct contact from other people (anthropophilic organisms), animals (zoophilic organisms), and soil (geophilic organisms), as well as indirectly from fomites. Dermatophyte infections can be readily diagnosed based on the history, physical examination, and potassium hydroxide (KOH) microscopy. Diagnosis occasionally requires Wood's lamp examination and fungal culture or histologic examination. Topical therapy is used for most dermatophyte infections. Cure rates are higher and treatment courses are shorter with topical fungicidal allylamines than with fungistatic azoles. Oral therapy is preferred for tinea capitis, tinea barbae, and onychomycosis. Orally administered griseofulvin remains the standard treatment for tinea capitis. Topical treatment of onychomycosis with ciclopirox nail lacquer has a low cure rate. For onychomycosis, "pulse" oral therapy with the newer imidazoles (itraconazole or fluconazole) or allylamines (terbinafine) is considerably less expensive than continuous treatment but has a somewhat lower mycologic cure rate. The diagnosis of onychomycosis should be confirmed by KOH microscopy, culture, or histologic examination before therapy is initiated, because of the expense, duration, and potential adverse effects of treatment.

Antifungal Agents↗

PubMed2003

[Prevalence of zoophilic dermatophytes in the Sarajevo region].

Zoophlic dermatophytes are common cause of tinea infections in Europe, especially in Mediterranean area. The aim of our study was to determine the prevalence of zoophilic dermatophytes in Sarajevo area, during a five-year period (1998-2002). Samples (skin scrapings or nail fragments) were taken from 2,142 patients who presented with suspected dermatophytoses and cultured on Sabouraud agar. After three weeks of incubations 465 (21.7%) dermatophytes were identified based on macroscopic and microscopic morphology. Zoophilic dermatophytes were found in 421 (90.5%) patients. The most common zoophilic species was Microsporum canis (80.0%), whereas Trichophyton mentagrophytes and Trichophyton verrucosum were less frequently isolated, in 9.7% and 0.9%, respectively. Lesions of tinea capitis were the most prevalent clinical type of Microsporum canis infections (28.8%), followed by tinea corporis (27.4%), tinea faciei (14.8%), tinea pedum (10.2%), tinea unguium (7.8%), tinea manuum (7.5%) and tinea cruris (3.5%). The findings in our study indicate a constant increase in frequency of the zoophilic microsporiasis in recent years in Sarajevo area.

Animals↗

PubMed2003

[The change of dermatophyte spectrum in dermatomycoses].

The spectrum of dermatophytes out of mycotic skin lesions had changed in last 70 years. Before the Second World War in Germany Microsporum audouinii and Epidermophyton floccosum held the first position, since the fifties of last century Trichophyton rubrum is the most frequently isolated dermatophyte accounting for 80-90% of the strains, followed by T. mentagrophytes. This development is typical for Central and North Europe and is connected with the increase in the incidence of tinea pedis. In contrast to this, in Southern Europe and in Arab countries zoophilic dermatophytes, such as M. canis and T. verrucosum, are the most frequently isolated dermatophytes. An analysis of the frequency and distribution of tinea pedis in different occupations and the route of infection is also reported. The epidemiologic findings are contrary to the assumption that patients are genetically predisposed to T. rubrum infection in a dominant autosomal pattern.

Arthrodermataceae↗

PubMed2005

[Enzyme activities of dermatophytes isolated from different clinical samples by ApiZYM method].

Dermatophytes' enzymes may have a role in chronic superficial infections. In this study it was planned to investigate the possible relationship between the enzymatic activities of the dermatophytes and acute or chronic course of the infections. Dermatophytes were isolated from 58 (72%) out of 81 patients with superficial infections. The infections were divided into two groups as acute (< or = 6 weeks) or chronic (> 6 weeks). Isolated fungi were identified by the classical methods and ApiZYM method. ApiZYM exhibits 19 different enzymatic activities. From 11 acute cases; five Epidermophyton floccosum, three Trichophyton rubrum, two Microsporum canis and one Trichophyton mentagrophytes strains were isolated. Of the 47 chronic cases, 96% was due to T. rubrum and 4% due to T. mentagrophytes. Production of alkaline phosphatase, leucine arylamidase and beta-glucosidase enzymes were detected in all tested strains. There was no difference between the enzymatic activities of acute and chronic cases. Alpha-mannosidase activity was detected in all of the species isolated from acute cases whereas none of the chronic cases were positive (P < 0.001). The results of this study suggest that alpha-mannosidase activity may play a role in both cutaneous inflammatory response caused by dermatophytes and the chronicity of the lesions.

Acute Disease↗

PubMed2005

[Dermatophytic disease in a Tunisian family].

Dermatophytic disease is a rare chronic infection caused by common dermatophytes and characterized by cutaneous and subcutaneous invasion. It is observed mainly in North Africa where it is presumably inherited via an autosomal recessive trait. Cellular immunodeficiency could account for the chronic nature of the disease and for its refractoriness to drug treatment. The purpose of this report is to describe the occurrence of dermatophytic disease in three sisters of consanguineous parents in a rural region of northern Tunisia. To our knowledge, this is the first familial case reported in Tunisia. The most salient features in these patients were early age of disease onset in three females, isolation of Microsporum canis at the beginning of the disease, relatively favorable course with long remissions in two cases, and absence of visceral involvement. Various drugs including antifungal agents and immunostimulants were used for treatment with disappointing results. Surgical excision associated with antifungal agents appeared to be effective in our patients. Dermatophytic disease remains a severe disease due to the possibility of potentially life-threatening visceral involvement.

Antifungal Agents↗

PubMed1991

Dermatophyte feet infection among students enrolled in swimming courses at a university pool.

The aim of this study was to determine the prevalence of dermatophyte feet infection among students enrolled in swimming courses at a university swimming pool. Tinea pedis infection was determined on two occasions. The first study took place on the first day of classes and the second on day twelve of swimming lessons. Culture and KOH examination of the interdigital skin scrapings of the left foot showed superficial foot infection with dermatophytes or Candida albicans in 13.2% of the students (11/83) in the first study, and in 22.2% of the students (16/72) in the second study. The most common agent of tinea pedis in the first study was Trichophyton rubrum (82%), infections by T. mentagrophytes (9%) and Epidermophyton floccosum (9%) were less common. At that time, no dermatophyte was recovered from any of 30 floor samples taken from the bathroom and pool facilities. In the second study the following dermatophytes were isolated from the student's feet: T. mentagrophytes (70.6%), T. rubrum (17.6%) and Candida albicans (11.8%). On this occasion T. mentagrophytes was recovered from 5 out of 30 floor samples. It is possible that the frequency of the use of the pool facilities may influence the prevalence of tinea pedis as well as the etiological agent involved in this disease.

Female↗

PubMed1989

[Dermatophyte flora in a catchment area of the Hamburg military hospital].

Our article deals with the evaluation of all mycologic examinations carried out at the mycologic laboratory of the Department of Dermatology, Hamburg Military Hospital, from April 1983 through March 1988. With regard to the growth of dermatophytes, 835 cultures were found positive out of a total of 10,000 specimens. Our list of dermatophytes is classified according to both the incidence of the individual pathogen and the part of the body it was found on. The most common dermatophyte was Trichophyton rubrum (78.2%). Our results are compared to those of previous studies on dermatophytes.

Arthrodermataceae↗