[Ecology of dermatophytes. I. Correlation between the dermatophyte infection and keratinophilic fungi from the soils of Rosario].
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Argentina↗
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[The effect of antifungal substances on the acid metabolism of dermatophytes. 7. Chemical and physiologic-chemical studies on dermatophytes].
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Antifungal Agents↗
[The effect of antifungal substances on the nitrogen distribution of dermatophytes. 8. Chemical and physiologic-chemical studies on dermatophytes].
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Amino Acids↗
[Biometric analysis of the natural variability of mycelial growth in dermatophytes macro-colonies on glucose-peptone agar during the exponential growth phase. I. Heterogeneity of the dermatophytes inoculum].
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Arthrodermataceae↗
Identification of carbon dioxide as a dermatophyte inhibitory factor produced by Candida albicans.
A factor produced by Candida albicans, which inhibits dermatophyte growth and induces arthrospore formation is characterized and identified. Candida dermatophyte inhibitory factor (CDIF) is volatile and fungistatic. Analysis of volatile materials produced by C. albicans was subsequently identified as carbon dioxide. The involvement of carbon dioxide in the inhibition of dermatophytes was demonstrated by: (1) utilization of commercial carbon dioxide to produce dermatophyte inhibition as well as arthrospore formation, and (2) prevention of dermatophyte inhibition by C. albicans through incoporation of soda lime into the incubation atmosphere. The ability of carbon dioxide to inhibit dermatophyte growth was shared with other gases (methane and helium), but arthrospore formation was observed only with carbon dioxide. The possible significance of carbon dioxide's induction of arthrospores, a form occasionally observed in active dermatophyte lesions, is discussed.
Antifungal Agents↗
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↗
[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↗
[Reflections on dermatophytes].
In light of his experiences especially in tropical regions, the author makes some remarks about dermatophytes and dermatophytia, which they cause. The following main items are: 1. The dermatophytes lead a saprophytic life. 2. Exceptionally, they can invade nonkeratinized tissue and cause "dermatophytic disease", perhaps mycetomas. 3. 45 percent of the ringworm of the scalp heal before puberty. 4. In the tropical regions, trichophytosis caused by endothrix-species are often of inflammatory nature, the favus appears often without scutula formation (afavic). 5. One can heal a substantial percentage of the ringworm of the scalp with a single dosis of 12 tablets (125 mg each) of fine particle griseofulvin. 6. Athlete's foot has also other causes than only dermatophytes.
Adolescent↗
The distribution of geophilic dermatophytes in Kenyan soils.
Two hundred and eighty one soil samples from different provinces of Kenya were examined for dermatophytes by the hair baiting technique. Dermatophytes were recovered from 84 samples. Microsporum gypseum constituted 75.8% of the total isolates while Keratinomyces ajelloi and M. cookei formed 21% and 3.2%, respectively. The distribution of the dermatophytes was influences by soil pH, being more prevalent in acidic than in alkaline soils.
Arthrodermataceae↗
Epidemiologic study of dermatophyte infections in Nigeria (clinical survey and laboratory investigations).
The commonest dermatophyte infection among the referred dermatology cases in Nigeria is tinea pedis, whereas among the surveyed population of school children, the commonest fungal infection was tinea capitis. It was found that the most ubiquitous causative organism for tinea pedis was E. fluccosum, that for tinea capitis was M. audouinii, while that for tinea corporis was T. soudanese. The source of infection of tinea capitis among the school children was found to be most likely the local barber who serviced the schools in all the villages, and this might explain the high incidence rate of T. soudanese in tinea capitis. Tinea pedis infection is believed to be highly favoured by the wearing of shoes among the senior students. Animals were not a major source of transmission of dermatophytes in Nigeria. No new species of dermatophytes has been identified among the cultured organisms.
Adolescent↗
Geographical distribution of the dermatophytes: a review.
In these days of rapid transit from continent to continent, and the increasing mobility of people, agents of disease are no longer geographically restricted. Disease contracted half way across the world may become manifest in a country in which the pathogen is not normally found. Thus knowledge of the geographical distribution of pathogens becomes increasingly important when a diagnosis is being made. This is as true of ringworm fungi as of any other group of microorganisms. In the last 12 years, in the Mycological Reference Laboratory, an increasing number of exotic dermatophytes have been seen, related in part at least to the great increase in the number of non-British residents. Not all species of dermatophytes are cosmopolitan in their distribution throughout the world. While some have been recorded from every continent, others have geographically limited areas of greater or lesser extent. Surveys taken at intervals in a country may show a rise and fall in occurrence of several species as habits change, populations move and medical facilities became increasingly well-distributed. There have been few geographical surveys of ringworm fungi that have covered the world. Ajello (1960, 1974) has reviewed the individual species with regard to geographical location, while Vanbreuseghem & de Vroey (1970) attempted to estimate the relative importance of the various species in terms of numbers of isolations reported. This paper therefore reviews the world dermatophyte flora in terms of the dominant agents in the various countries, and some of the changes that have been recorded.
Africa↗
Experimental inoculation of dermatophytes on psoriatic skin.
Two dermatophytic agents, Trichophyton rubrum and Trichophyton mentagrophytes were used in the experimental inoculation of psoriatic lesions in 27 volunteer patients (13 males and 14 females with an age range from 17 to 72 yr). T. rubrum was inoculated in 14 patients and T. mentagrophytes (varietas granulare) in 13. For purposes of control in each patient the same agent was also inoculated on healthy skin. Results were noted once a week for a period of 1 mo. A positive response was found in 12 of the 14 patients inoculated with T. rubrum but only in 4 of the 13 inoculated with T. mentagrophytes. Healthy skin was found to have a positive response in only 5 cases, in 4 with T. rubrum, and in 1 with T. mentagrophytes. These results confirm the possibility of invasion of psoriatic lesions by dermatophytes and suggest that the coexistance of psoriasis and dermatophytic infection may be not always purely coincidental. The importance of the awareness of the presence of mycotic lesions and their possible spread with the application of steroid ointments under occlusive dressings in a psoriatic patient is stressed.
Adolescent↗
Isolation of glycopeptides with skin test activity from dermatophytes.
By using ethylene glycol extraction of whole submerged cultures followed by Sephadex G-200 and diethylaminoethyl-Sephadex chromatography, we isolated four distinct glycopeptides from Trichophyton mentagrophytes, T. rubrum, and Microsporum canis. Chemical analyses revealed that these glycopeptides contained mostly carbohydrate (42.5 to 81.6%) and protein (4.3 to 11.3%), with lesser amounts of phosphorus (0.4 to 6.0%) and hexosamines (0.3 to 0.6%). Based upon total carbohydrate and monosaccharide content, these dermatophyte glycopeptides could be divided into two chemical groups: glucopeptides (DSI1) and mannopeptides (DSI2, DSII1, and DSII2). The mannopeptides and glucopeptides of each species of dermatophyte were not significantly different chemically from those derived from the other two dermatophyte species studied. Skin testing of DSI1-glycopeptides or DSI2-mannopeptides in immunized guinea pigs indicated that only the DSI2-mannopeptides elicited a delayed hypersensitivity reaction. Skin testing T. mentagrophytes 62-infected guinea pigs with the four purified DS-glycopeptides, as well as earlier fractions from the purification scheme, derived from T. mentagrophytes, T. rubrum, and M. canis, again indicated that only the DSI2-mannopeptides of the two Trichophyton species elicited a delayed hypersensitivity reaction. The number of infections or duration of infection had no effect on the size of the skin test response. DSI2-mannopeptides were non-cross-reactive between genera when tested in Trichophyton-immunized or -infected guinea pigs and Microsporum-immunized guinea pigs.
Animals↗
Suppression of in vitro lymphocyte transformation during an experimental dermatophyte infection.
During primary Trichophyton mentagrophytes infection of strain 2 guinea pigs, the colony-forming units (CFU) of fungi present within the lesion peaked between days 7 and 14, whereas the severity of the lesion itself peaked between days 11 and 16. Concomitant with the latter peak, a pronounced depression in the in vitro mitogenic activity of spleen cells (SPC) and lymph node cells (LNC) was observed. Only after resolution of the primary infection (day 21) did LNC show increased deoxyribonucleic acid (DNA) synthesis in the presence of fungal antigens. During cutaneous reinfection, there was no distinct peak fungal load and CFU appeared to decrease steadily during the accelerated course of a reinfection disease. LNC from guinea pigs with severe, ulcerated reinfection lesions generally exhibited a heightened response to fungal antigen in vitro. LNC from guinea pigs with mild reinfection dermatophytosis had depressed in vitro reactivity to mitogens and dermatophyte antigen. The suppression of blastogenic activity during dermatophyte infection appeared to be associated with autologous serum components, since increased DNA synthesis resulted when SPC or LNC were cultured with fetal calf serum. The depressed in vitro DNA synthesis of lymphocytes (cultured with dermatophyte antigens) that were harvested during reinfection was not accompanied by an impaired ability of infected guinea pigs to respond with a delayed-type hypersensitivity skin test in vivo. These results support the hypothesis that experimental T. mentagrophytes dermatophytosis is a cell-mediated hypersensitivity disease that can be modified by immunosuppressive control mechanisms elaborated or induced by the fungus.
Animals↗
[Opportunism in dermatophytes].
Dematophytes invade hosts when their state is suitable for the production of their pathogenicity. When the host's resistance is reduced, the prevalence of dermatophytoses can be extremely high or the symptomatology can be very unusual. It is suspected that the 'maladie dermatophytique' and pherhaps dermatophytic mycetoma develop in such situations. The fact is that the behaviour of dermatophytes does not differ from that of the so-called opportunistic fungi and in some cases it is possible to speak of dermatophytic asthenomycosis.
Arthrodermataceae↗
[13 Years of veterinary mycological routine diagnostics. Isolation of dermatophytes in the years 1965-1977].
Over a thirteen year period (1965 to 1977) a total of 4790 skin scrapings and hair samples of animals were examined mycologically. 887 strains of dermatophytes were isolated out of 885 of these samples (= 18,5%). Most frequently Trichophyton verrucosum was identified in samples from cattle, followed by Microsporum canis isolated from cats, dogs and zoo animals. T. mentagrophytes was mainly found on guinea pigs, chinchillas and dogs and T. equinum on horses. Although the total number of the samples examined within the last 8 years increased, the total of the dermatophytes isolated remained proportionately the same. The relative numbers of the various species of dermatophytes isolated did not change within the period of investigation.
Animals↗
Keratin decomposition by dermatophytes. II. Presence of s-sulfocysteine and cysteic acid in soluble decomposition products.
The dermatophyte Microsporum gypseum was grown on human hair in a mineral medium. Filtrates of cultures of various age were chromatographed on Sephadex gels and further characterized by chemical analysis and thin-layer chromatography. The products of keratin decomposition were separated into two fractions. The first fraction formed 10 to 20% of the bulk and contained proteins low in sulfur content. The second, very wide fraction contained oligopeptides and polypeptides with molecular weights from several hundreds up to approximately 13,000 with a peak at 1,000-2,000 daltons. This fraction contained a relatively high amount of cystine, S-sulfocysteine, and cysteic acid. S-sulfocysteine was present in the free state and also combined in peptides where its amount exceeded that of cystine. This supports the author's hypothesis on keratin decomposition by dermatophytes. According to this hypothesis, the fungus excretes sulfite which cleaves the disulfide bonds of keratin to cysteine and S-sulfocysteine. The substrate, denatured by sulfitolysis, is then more easily digestible by fungal proteases. Besides S-sulfocysteine, comparable amounts of cysteic acid were found in all analyses. This compound most probably originated by air oxidation of sulfur amino acids in the alkaline cultivation fluid.
Biodegradation, Environmental↗
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.
Animals↗