The distribution of geophilic dermatophytes in Kenyan soils

Dermatophytes and dermatophytosis in the eastern and southern parts of Africa

Dermatophytosis is currently a disease of global importance and a public health burden. It is caused by dermatophytes, which attack and grow on dead animal keratin. Dermatophytes belong to three genera, namely, Epidermophyton, Microsporum, and Trichophyton. The predominant clinical forms and causative agents vary from one region of the world to another. Poor socioeconomic status, high population densities, and poor sanitary conditions are some of the factors responsible for the high prevalence of dermatophytosis in many developing countries, which include countries in southern and eastern Africa, the focus of this review. To the best of our knowledge, there is currently no review article on published findings on dermatophytosis in the eastern and southern parts of Africa. This information will be of interest to the medical and research community since the world has become a global village. This review covers published research findings in eastern and southern regions of Africa until this date. The countries covered in the current review include Kenya, Ethiopia, Tanzania, South Africa, Mozambique, Madagascar, Malawi, Rwanda, Burundi, Uganda, Zambia, Zimbabwe, and Botswana. T. violaceum is the most common human etiological agent in all the countries under review with prevalence ranging from 56.7% to 95%, except for Madagascar (M. langeronii, reclassified as M. audouinii), Uganda (M. gypseum) and Malawi (M. audouinii). Tinea capitis was the most clinical type, followed by tinea corporis. Etiological agents of animal dermatophytoses were variable in the countries where they were reported. Major risk factors for dermatophytoses are age, climatic, and socioeconomic factors.

A preliminary study on the occurrence of keratinophilic fungi in soils of Jamaica

This report represents the first study of keratinophilic fungi present in soils of Jamaica. Out of the 40 soil samples examined from different habitats, 30 (75%) were positive for the presence of keratinophilic fungi, yielding 36 isolates of keratinophilic fungi. Microsporum gypseum complex (represented by 16 isolates of M. gypseum, and four of M. fulvum) was most frequent, being present in 50% of the samples. A very high occurrence of this dermatophyte in Jamaican soil is of public health significance. The remaining isolates of keratinophilic fungi were represented by Chrysosporium spp (mainly C. indicum and C. tropicum) and Sepedonium sp.

Epidemiological investigation of keratinophilic fungi from soils of Djerba (Tunisia)

INTRODUCTION

Epidemiological investigation of keratinophilic fungi in soil has been carried out in different parts of the world. However, our knowledge of the present occurrence and distribution of keratinophilic fungi in Tunisian soils remains unknown. This study was carried out to evaluate the epidemiological characteristics of keratinophilic fungi in the soils collected in Djerba (South of Tunisia).

MATERIAL AND METHODS

One hundred and forty one soil samples were collected from various sites in Djerba and screened for the presence of keratinophilic fungi and related dermatophytes using hair-baiting technique. Fungi were identified using macro- and micro-morphological features.

RESULTS

Among them, 29 (20.6%) soil samples were positive. Seven species were isolated in the following order of dominance: Chrysosporium keratinophilum (48.3%), Microsporum gypseum (41.4%), C. tropicum (10.4%), C. parvum (3.45%), C. anamorph of Anixiopsis stercoraris (3.45%), C. anamorph of Arthroderma cuniculi (3.45%) and Chaetomium sp. (3.45%). The association of M. gypseum and C. keratinophilum was detected in 13.8% of positive soils. Sixty-nine percent of fungi were found in organic matter rich soil. Our results revealed a higher prevalence of keratinophilic fungi in the regions far from the sea (33.3%) than in those near the sea (11.1%) with a statistically significant difference (P=0.001). All keratinophilic fungi were isolated from soils with pH ranging from 6.2 to 7.6.

CONCLUSION

Our study showed that keratinophilic fungi were present in the various soils of Djerba. They may represent a risk to human health.

Distribution of dermatophytes and other related fungi in Jaipur city, with particular reference to soil pH

Screening of 217 soil samples of different habitats, such as PG study centre, garden, farmhouse, nursery, roadside, hostel, animal habitat, bird habitat, marriage garden, temple, vegetable market and house dust, was carried out for the presence of dermatophytes and related fungi in relation to soil pH. A total of 461 isolates belonging to 26 genera and 34 species were recorded. Soil pH values vary from 3 to 10.5. Trichophyton verrucosum, Microsporum audouinii and M. canis were isolated for the first time in Jaipur from pH range 7.0 to 9.0. Chrysosporium tropicum (46.08%) was the most predominant fungus isolated from pH range 6.5 to 9.5. Trichophyton mentagrophytes (24.88%) was the second most common fungal species isolated from pH 6.5 to 9.5. Most of the keratinophilic fungi were isolated from pH 6.5 to 8.5. Only one isolate of Fusarium moniliforme was reported from a highly acidic site at pH 3. Roadside and garden soils were found to be the most suitable sites for almost all keratinophilic fungi.

Keratinophilic fungi of poultry farm and feather dumping soil in Tamil Nadu, India

Soils of 10 poultry farms from Namakkal and 12 feather dumping sites from Chennai were studied for the presence of keratinophilic fungi. A total of 34 species belonging to 19 genera and one non-sporulating fungus were recovered. Sixteen species of fungi and one non-sporulating fungi were common to both sites, eight species were specific to Namakkal and nine species were specific to Chennai. Dermatophytes and closely related fungi were represented by six species belonging to five genera. Fungal species commonly found in the soil samples included Chrysosporium keratinophilum (73%), Trichophyton mentagrophytes (68.2%), Microsporum gypseum (64%), Myceliopthora vellerea (32%), Chrysosporium state of Arthroderma tuberculatum (27.3%) and Geomyces pannorum (23%). Non-dermatophyte fungi were represented by 28 species belonging to 14 genera and one non-sporulating fungus.

Incidence of keratinophilic fungi in the soil of primary schools and public parks of Madras City, India

The pattern of incidence of keratinophilic fungi inhabiting the soil of 30 primary schools and 15 public parks in the city of Madras was studied using hair baiting technique. A total number of 31 species belonging to 15 genera were recovered, 16 of which were common to both the school and public park soil. Dermatophytes and closely related species were represented by 9 species, of which the following were the most commonly found species in soil: Chrysosporium tropicum (62.2%), C. keratinophilum (48.8%), M. gypseum (48.8%), C. pannorum (40%), T. mentagrophytes (37.7%), T. terrestre (31.1%) and C. anam. A. cuniculi (24.4%). The fungi encountered have also been discussed in relation to their global distribution.

Impact of some ecological factors on the occurrence of poultry soil-inhabiting keratinophiles

Investigations were conducted to assess the ecological factors governing distribution and survival of keratinophilic fungi in poultry farm soils. All the poultry farm soils were rich in humus and the keratinophilic fungi were generally found to be proportional to the soil organic matter. These soils were nearly neutral to weakly alkaline and organically rich with a high content of organic carbon, nitrogen, phosphorus, potassium, magnesium, calcium and iron.

Soil dermatophytes in Madras, India, in relation to human ringworm

A total of 269 soil samples collected from different habitats in Madras, India, were screened for the presence of dermatophytes by the hair-baiting technique. Three strains of Trichophyton mentagrophytes and 16 strains of Microsporum gypseum complex were isolated. These strains were subjected to the mating experiment. 2/3 soil isolates of Trichophyton mentagrophytes belonged to Arthroderma vanbreuseghemii (+) mating type, and 1/3 was Arthroderma vanbreuseghemii (-) mating type. Similarly 6/70 clinical strains of Trichophyton mentagrophytes isolated in our previous study also belonged to Arthroderma vanbreuseghemii (+) mating type. These 6 strains were isolated from severe cases of tinea capitis in children belonging to rural Madras. The teleomorphic and mating type homology between the clinical and soil isolates of T. mentagrophytes suggest that soil may act as reservoir for these organisms. The incompatible clinical strains of T. mentagrophytes var. interdigitale and A. vanbreuseghemii showed DNA homology, thereby establishing the epidemiologic link which supports the above findings.

Isolation of dermatophytes and other keratinophilic fungi from surface sediments of the Shatt Al-Arab River and its creeks at Basrah, Iraq

Twenty-five sediment samples were taken from randomly selected sites in the Shatt Al-Arab River and its creeks and analysed for dermatophytes and related keratinophilic fungi. The results revealed that out of 25 samples only 13 (52%) yielded dermatophytes and related keratinophilic fungi. A total of nine species in four genera were isolated. The most frequent genera isolated in this study were Chrysosporium and its teleomorph Aphanoascus. The species most frequently found were Aphanoascus fulvescens, A. durus, Chrysosporium crassitunicatum, Chr. keratinophilum and Chr. tropicum (each n = 3). Microsporum was represented by two species, namely M. fulvum and M. gypseum. Trichophyton was represented by one species, T. verrucosum. The occurrence of these fungi illustrates that sediments may act as a reservoir for potentially pathogenic fungi for human and animals.

Screening of different keratin baits for isolation of keratinophilic fungi

Twenty different keratin-rich substrates were screened as keratin baits for isolation of keratinophilic fungi from different soil sample of Chhindwara District, India. Fungi easily formed colonies on different baits. However, hair, feathers and horns were found to be more suitable than nails, fish fins and fish scales.

Keratinolytic and keratinophilic fungi in the soils of Papua New Guinea

A study was made of soil samples collected during an expedition to the Highlands of Papua New Guinea. Fungi were isolated from the samples by the method of hair baiting (To-Ka-Va). Of the 33 species isolated, about half showed keratinolytic activity. Such activity is previously unreported for Mucor hiemalis f. hiemalis, Myrothecium roridum, Paecilomyces carneus, P. marquandii, Penicillium brevicompactum, Rhinocladiella mansonii and Verticillium lecanii. The species most active keratinolytically were Chrysosporium an. Arthroderma cuniculi, C. an. A. curreyi, C. indicum, Myceliophthora vellerea and Trichophyton ajelloi. The spectrum of fungi with keratinolytic activity isolated from the different sites differed considerably according to the frequency of use by man, heaviest use being correlated with greatest activity. The pH of the soil (varying from 5.8-7.5) had little influence on the type of such fungi isolated.

Distribution of keratinophilic fungi in desert soil of Kuwait

Forty soil samples from different desert localities in Kuwait were surveyed for keratinophilic and geophilic dermatophytic fungi. Sixteen species classified in 9 genera were recovered on wool baits. Chrysosporium species were the most common fungi: Chr. tropicum (60%), Chr. pannicola (32.5%), Chr. queenslandicum (27.5%), Chr. keratinophilum (25%), Chr. indicum (20%) and the Chrysosporium anamorph of Arthroderma cuniculi. The second dominant genus was Malbranchea (27%) represented by two species; followed by Myceliophthora (10%). A number of cleistothecial keratinophilic species were also reported in restricted areas. Ctenomyces serratus Eidam and its Myceliophthora anamorph were new records to Kuwait. The frequency and distribution of these fungi have been discussed in relation to ecological conditions of desert soils.

Keratinophilic fungi of school playgrounds in the Nablus area, West Bank of Jordan

The distribution of keratinophilic fungi in the soil of 57 school playgrounds in the Nablus area was studied with relation to human presence. A total number of 73 species was recovered. Thirteen of these species were dermatophytes and closely related fungi. The most common and frequent species of the latter fungi were: Arthroderma cuniculi (found in 32.1% of school playgrounds), Chrysosporium keratinophilum (32.1%), Microsporum gypseum (10.7%), T. terrestre (7.1%), and C. asperatum (7.1%). Twenty eight of the isolated species had been reported to be pathogenic; these comprised 64.3% of the keratinophilic mycoflora of school playgrounds.

Keratinophilic fungi isolated from children's sandpits in the Nablus area, West Bank of Jordan

The keratinophilic fungi of 29 sandpits from kindergarten schools and public parks in the city of Nablus was analysed to evaluate their role in the epidemiology of diseases caused by these fungi. Seventy two species were recovered 28 of which were common to both kindergartens and public parks sandpits. High percentage (57.4%) of fungal isolates found had been identified as the causes of various types of mycoses. Eight species of dermatophytes and closely related fungi were recovered, of which the followings were the most commonly found species in sandpits: Chrysosporium keratinophilum (20.7%), Microsporum gypseum (17.2%), Trichophyton mentagrophytes (6.9%), and C. evolceanui (6.9%).

Keratinophilic fungi from Nigerian soil

During a survey of keratinophilic fungi in Nigerian soil samples, twelve species of fungi were isolated. These included Chrysosporium keratinophilum, C. tropicum, Curvularia lunata, Microsporum audouinii, M. canis, M. fulvum, M. gypseum, M. vanbreuseghemii, Trichophyton ajelloi, T. mentagrophytes, T. soudanense and T. yaoundei. These keratinophilic fungi had a higher incidence by occurrence of individual species during the rainy season (May-October) than the dry season (November-April).

Keratinolytic and keratinophilic fungi of children's sandpits in the city of Turin

Soils rich in keratinic residues constitute a permanent or occasional reservoir for dermatophytes and keratinolytic and keratinophilic fungi, and are a source of potential infection for man and animals. The keratinolytic and keratinophilic mycoflora of 28 sandpits in Turin was studied to evaluate the risk of fungal skin infections that is run by children as they play in public parks and to lay the ground-work for a next epidemiological study of soil- and animal-inhabiting dermatophytes found in cities, and their impact on human dermatophytoses. Fifty seven species were isolated and a high percentage (52%) showed keratinolytic activity. Species of Microsporum, Trichophyton, Mariannaea, Aphanoascus, Chrysosporium, Malbranchea and Geomyces showed the most active keratinolysis.

[Demonstrated significance of fungal flora in sand-boxes]

In order to evaluate the risk of fungal contamination in sand-boxes of the city of Angers' game areas, the authors took 100 samples of sand from different environments: parks, gardens, buildings, nursery schools. They report the presence of a varied and important mycoflora and that the frequency and the distribution are more sensitive to the techniques used to isolate the fungus, as well as to the quality of the sand and to the eco-mesological factors in the four studied areas. The examination of earth samples has allowed the findings of a great number of keratinophilie species. The strains living in the sand do not represent a real danger of infection for the children.

Epidemiology of dermatophytosis in the metropolitan area of Turin

The study here presented deals with the problem of the dermatophytoses in Piedmont, with regard to their etiologic and, more generally, their epidemiologic aspects. From 586 patients who presented themselves at the Dermatology Clinic of the University of Turin, for mycological examinations, between the period of March-November 1979, 100 positive cases were selected. The study was set under way with the filling in of special forms for the epidemiologic investigation and with the classification of some species of fungi which had been isolated beforehand, using the methods of Ajello, Rebell and Taplin (1, 12). From the data collected, it was ascertained that the principal etiologic agents isolated were, in order of frequency: Microsporum canis, Tricophyton rubrum, Epidermophyton floccosum and T. mentagrophytes. The subjects that were affected most by these dermatophytes were the young (babies and schoolchildren) with the location of the infections being mostly in the scalp. As regards the period of manifestation, May - June and September - October were the periods with the highest incidence. It is noteworthy that the diffusion of the principal dermatophytes could be attributed to domestic animals such as cats and dogs.

Investigation of keratinophilic fungi from soils in western Australia a preliminary survey

In order to determine which species of geophilic dermatophytes were present in Western Australian soils 299 samples were investigated. These samples were collected from a range of locations, 208 towns throughout the state and 91 samples from the Perth Metropolitan area. Most samples were collected from areas frequented by people and animals, such as home gardens, parks and animal yards. Of the total 299 soils, 271 (90.6%) yielded keratinophilic fungi. A total of 181 dermatophytes were isolated, and there were 205 isolations of other keratinophilic fungi. Microsporum gypseum (30.7%) was the most prevalent dermatophyte recovered from soil followed by Microsporum cookei (21.7%) and then Trichophyton ajelloi (8.0%). No other dermatophytes were recovered. Chrysosporium indicum was the most common of all the keratinophilic fungi and was isolated from 50.1% of the samples. Mixed growth was obtained from 33.5% of the soil samples.