Ecology of dermatophytes and other keratinophilic fungi in swimming pools and polluted and unpolluted streams

The biodiversity and richness of keratinophilic fungal communities including dermatophytes were assessed in three stream sites and three swimming pools in the Nablus district in Palestine, using hair baiting (HBT) and surface dilution plate (SDP) techniques, over 8- and 6-month periods, respectively. The effect of waste water effluent and selected ecological factors on these fungi in relation to species diversity and population densities were also considered. Fifty keratinophilic fungal species were recovered from the aquatic habitats studied, of which 42 were recovered from stream sites and 22 from swimming pools. Of these fungi 6 were either dermatophytes (Microsporum gypseum, and Trichophyton mentagrophytes) or dermatophyte related species (Chrysosporium merdarium, Ch. tropicum, Ch. keratinophilum and T. terrestre). The most frequently isolated species in the three pools were Acremonium strictum and Cladosporium cladosporioides, using Sabouraud dextrose agar medium (SDA). The most abundant species were Acr. strictum, and Aspergillus flavus. However, only 4 species were isolated using the SDA medium amended with 5-flurocytosine (5-FC). The most frequent and abundant species in the three stream sites using SDA medium were Geotricum candidum, and Penicillium chrysogenum. The most frequent species in the three sites using the 5-FC medium, was Paecilomyces lilacinus. Using HBT, the most abundant and frequent species in the three stream sites were G. candidum, and Pa. lilacinus, on SDA medium, and Pa. lilacinus, and Gliocladium nigrovirens on the 5-FC medium. The 5-FC medium was more suitable for the isolation of dermatophytes and closely related species than the SDA medium; 6 were recovered on 5-FC, whereas only one on the SDA medium. Variation in the levels of keratinophilic fungal populations from the three stream sites sampled 5 times over an 8-month period, followed comparable fluctuation patterns. Waste water affected fungal population densities with the highest levels in the un-polluted stream sites, and lowest in the heavily polluted sites. Swimming pools, polluted and un-polluted stream sites were found to be rich in pathogenic and potentially pathogenic fungi.This revised version was published online in October 2005 with corrections to the Cover Date.     

Ecology of cycloheximide-resistant fungi in field soils receiving raw city wastewater or normal irrigation water

The effect of raw city wastewater irrigation on biodiversity and population densities of a cycloheximide-resistant (CH) fungal community was studied in 13 field soils receiving either raw city wastewater or normal irrigation, and in raw city wastewater in the Nablus area, using the hair baiting technique (HBT) and a surface soil dilution plating (SSDP) technique. Three of these fields [one had been receiving raw city wastewater for more than ten years and was designated a heavily polluted field, and the other 2 were cultivated for the first time and were either irrigated with raw city wastewater (newly polluted field) or normal irrigation water (nonpolluted)], were sampled 4–7 times over a 9-month period. The other ten fields, which had been under raw city wastewater irrigation for more than 10 years, were sampled only once. Fifty-seven CH-resistant species belonging to 18 genera were recovered, of which 49 species were recovered from soil habitats and 28 species from raw city wastewater. The HBT had shown to be more efficient in the isolation of pathogenic and potentially pathogenic fungi including dermatophytes. A higher percentage of this group of fungi was recovered from the three main field soils studied using HBT (70% of all isolates), than the SSDP (35.5%); no dermatophytes were recovered by the SSDP method. Two dermatophytes (Microsporum gypseum, and Trichophyton ajelloi), and five more fungi (Arthroderma cuniculi, A. curreyi, Chrysosporium keratinophilum, C. tropicum, and C. pannorum), were recovered from these habitats. Wastewater irrigation seemed to have affected the fungal population densities, with the highest population densities being found in the heavily polluted field soil, while lower population densities were found in the nonpolluted field soil. Increases in organic matter were also observed as a result of sewage effluent irrigation. However, basic similarities in the biodiversity of CH-resistant fungal communities existed in nonpolluted and polluted field soils, and raw city wastewater. Comparable numbers of fungal species were recovered from the three main field soils. The species most commonly found in those habitats included: Alternaria alternata, Aspergillus candidus, Geotrichum candidum, and Paecilomyces lilacinus. Field soils receiving either raw city wastewater or normal irrigation water, were found to be rich in pathogenic and potentially pathogenic CH-resistant fungi, including dermatophytes, with raw city wastewater yielding the highest percentage (81%), followed by the newly wastewater irrigated field (77.7%), the nonpolluted field (67%), and the heavily polluted field (63.4%). Hygienic measures should therefore be taken to control the spread of these fungi in the environment of human communities, and to avoid mycotic infections among farmers. This revised version was published online in August 2006 with corrections to the Cover Date.     

华东地区根结线虫寄生真菌调查*

通过对5种分离根结线虫寄生真菌的方法的比较,发现通过雌成虫平板分离法和卵平板分离法有较高的成功率,其他三种自幼虫上或土壤中分离的方法很少取得成功。从华东地区104个根结线虫样品中分离得到根结线虫寄生真菌638个菌株, 鉴定为14个属22个种,其中Cylindrocarpon destructans, C.heteronema, Fusarium equiseti, F.lateritium, F.proliferatum, Gliocladium virens, Humicola fuscoatra, Idriella lunata, Trichoderma hamatum, T.harzianum, Verticillium catenulatum, Volutella ciliata 为首次报道在根结线虫上寄生。通过种群分析发现Fusarium solani出现频率最高, F. oxysporum, Paceilomyces lilacinus 和 Acremonium strictum为常见种,这些种在根结线虫上广泛分布。同时还发现卵和成虫寄生真菌有所不同,Gliocladium virens 和Trichoderma harzianum仅在卵上分离到,而Volutella ciliata, Trichoderma hamatum 和Idriella lunata仅在雌成虫分离到,从幼虫上仅分离一次Paecilomyces lilacinus。其它真菌在卵和成虫上均可分离得到,真菌种类在三种根结线虫上和在不同地区有所不同。     

Hair and scalp mycobiota in school children in Nablus area

Hair and scalp mycobiota of 1389 clinically normal children aged 6–12 years attending 12 schools in the Nablus District, Palestinian Authority, was assessed on three occasions over 8-month period (October 1998–May 1999) using the hair brush technique. One hundred and one fungal species belonging to 33 genera were recovered: 6 dermatophytes, 16 dermatophyte-like keratinophilic fungi, and 79 other keratinophilic fungal species. Species varied considerably in their frequency of occurrence and abundance based on their relative importance values (RIVs). The most frequent and abundant species were: Cladosporium cladosporioides, Cl. herbarum, Penicillium chrysogenum and Aspergillus flavus. Microsporum canis, Aphanoascus fulvescence and Chrysosporum sulfureum were the most frequent and abundant species of all dermatophytes and dermatophyte-like keratinophilic fungi recovered. The most frequent and abundant dermatophytes in different communities were M. canis in rural (RIV 0.87) and urban children (0.45), and Trichophyton violaceum (1.41) in refugee camp children. Chrysosporium species were the most frequent and abundant dermatophyte-like keratinophilic fungus in children from all localities followed by Aphanoascus fulvescence. Comparable results on the frequency and abundance of human hair and scalp mycobiota component fungi were obtained based on age group and sex of children. Higher number of species was recovered in spring months (73 species) than in autumn (57) and winter (44) months. Similar occurrence pattern was also noted for dermatophyte-like keratinophilic species and dermatophytes. Higher percentages of children with moderate (11–50) and heavy (≤ 50) spore loads (7.54 and 0.73, respectively) were found in urban school children community than in rural and refugee camp school children (4.7 and 0.1, respectively). Also significantly higher light (1–10) spore load percentages were found in rural (63.67) and refugee camp (62.9) than in urban children (52.6). Of all localities, school children with light spore load comprised the highest percentage of the children examined (37.4), followed by moderate (6.13), and heavy (0.41) spore load categories. However, children with undetected spore load comprised 36.05% of all children. Spore load distribution did not show clear seasonal variations in the study period. Higher percentages of moderate and heavy spore loads were found in male children (8.72 and 0.69, respectively) than in female children (3.4 and 0.1, respectively). However, higher percentages of undetected (38.3) or light spore loads (58.4) were found in females than in males (34.04 and 56.53, respectively). This revised version was published online in June 2006 with corrections to the Cover Date.     

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 from 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 byMicrosporum cookei (21.7 %) and thenTrichophyton 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.     

Dermatophytes and other keratinophilic fungi causing ringworm of horses

From 60 horses showing skin lesions, 42% were positive for fungal infection. Horses less than 2-year old were more susceptible to this infection. Fourteen species belonging to nine genera of kerationphilic and cycloheximide-resistant fungi were recovered from collected specimens.Trichophyton was the dominant genus of whichT. equinum was the most common. This species proved to be the main causative agent of ringworm in horses. In addition to dermatophytes, many species of the isolated fungi were keratinophilic. The presence of such fungi on hairs and skin of horses may create an opportunity for them under special circumstances to become invasive to the skin or hair and thus cause primary or secondary infection of the animals.     

Dermatophytes and other associated fungi isolated from ringworm lesions of camels

Among 75 camels showing skin lesions, 48% were positive for fungal infection. The younger individuals were more susceptible to this infection. Sixteen species belonging to nine genera of keratinophilic and cycloheximide-resistant fungi were recovered from diseased camels.Trichophyton, Microsporum andChrysosporium were the most common genera.T. verrucosum appeared to be the main causer of ringworm in small camels whileT. mentagrophytes infected older ones. Camel skin presents a suitable habitat for the growth of some dermatophytes and other potentially pathogenic fungi.     

Keratinophilic Fungi Isolated from Soils of Long-Term Fold-Grazed, Degraded Pastures in National Parks of Slovakia

A total of 939 isolates of 11 genera representing 15 species of keratinophilic fungi were isolated and identified from the soils of three long-term fold-grazed pastures in national parks of Slovakia (Pod Ploskou, Strungovy príslop, and Pod Ke?kou) and one non-fold-grazed pasture in sierra Stolicke vrchy (Diel) using the hair-baiting technique. Keratinophilic fungi were present in all soil samples with a prevalence of Trichophyton ajelloi and Paecilomyces lilacinus. These fungi were more abundant in soil from fold-grazed pasture (Strungovy príslop) compared to non-fold-grazed pasture (Diel). The occurrence of the other keratinophilic fungi was substantially lower, likely because of low pH in some soils.     

The isolation of keratinophilic fungi from African soils

Summary Twenty-seven soil samples from Kenya and 9 from Egypt were investigated for the presence of keratinophilic and pathogenic fungi. No systemic pathogenic fungi was obtained, while a total of 25 dermatophytes belonging to four species was isolated. The majority of the Kenya isolates belonged toM. gypseum, while Egyptian isolates belonged toT. mentagrophytes. Shady sites frequented by humans or animals produced higher incidences of dermatophytes in Kenya than those of the unshady isolated areas.     

Keratinophilic fungi on the hair of goats from the West Bank of Jordan

The mycoflora of the hair in 178 goats from the West Bank of Jordan was analysed and the frequency of occurrence and the relative importance value for the different keratinophilic fungi found were calculated. One hundred and seven species which belong to 38 genera were isolated. Thirty six of these species were either well recognised agents of mycoses (Trichophyton mentagrophytes, T. verrucosum, and M. nanum), or have been frequently isolated from human and animal lesions (Arthroderma spp., Acremonium kiliense, Alternaria alternata, Aspergillus flavus, Cladosporium carionii, and several other species). These potentially pathogenic fungal species comprised 66.9% of all keratinophilic fungi found on the hair of goats. The role of this animal as a reservoir for dermatophytes and other potentially pathogenic fungi is discussed.     

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%).     

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.Work n. 315 performed under the auspices of the Centro di Studio sulla Micologia del Terreno del C.N.R. at the Dipartimento di Biologia vegetale dell Università di Torino.     

Survey of keratinophilic fungi isolated from city park soils of Pisa,Italy

A survey of geophilic dermatophytes and related keratinophilic fungi isolated from city park soils of Pisa is reported. Twenty-three (48%) soil samples out of 48 were positive by hair baiting. The following species were isolated: Microsporum gypseum (39%), Trichophyton ajelloi (31%), Chrysosporium keratinophilum (14%), T. terrestre (8%), M. fulvum, Ch. luteum, Ch. indicum (5% each) and M. cookei (2%). The presence of the different species is discussed in relation to the risk of fungal skin infections. This revised version was published online in June 2006 with corrections to the Cover Date.     

Keratinophilic fungi on the hair of cows,donkeys, rabbits,cats, and dogs from the West Bank of Jordan

The mycoflora of hair of 111 cows, donkeys, rabbits, cats, and dogs were analysed and the frequency of occurrence and the relative importance value of the different fungal species isolated were calculated. Total numbers of species 56, 45, 48, 23, and 11 were recovered from cows, donkeys, rabbits, cats, and dogs respectively. The majority of the keratinophilic fungi isolated were either well-known mycotic agents or have been recovered from various animal and human lesions. These comprised 87.8%, 66.7%, 61.4%, 59.3%, and 55.2% of the hair mycoflora in cats, dogs, rabbis, cows, and donkeys respectively. Seven species of dermatophytes were isolated: Trichophyton mentagrophytes, T. verrucosum, Microsporum gypseum, M. nanum, T. ajelloi, and M. canis. Cats harboured the largest number of dermatophytes (5 species), followed by cows (4 spp), rabbits (3 spp), and donkeys and dogs (1 sp). The role of these animals in the persistence and transmission of pathogenic fungi is discussed.     

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 inhabiting floor dusts of student houses at the South Valley University in Egypt

Keratinophilic fungi include true fungi that vigorously degrade keratin as well as a number of important human pathogenic dermatophytes. We identified 41 species and one variety belonging to 19 genera in 50 floor dust samples following culture on Sabouraud’s dextrose agar medium at 28°C. Dermatophytes and closely related fungi were represented by six species—Aphanoascus fulvescens, Aphanoascus sp., Arthroderma cuniculi, Chrysosporium lucknowense, Gymnoascus uncinatus and Trichophyton rubrum. There were 35 species and one variety of other fungal species, with members of Aspergillus and Penicllium being the most prevalent. Twenty-seven species and 1 variety belonging to 14 genera were identified from 24 dust samples gathered at 2-week intervals from male student housing at El-Kenose during January–December 2005 that had been cultured on Sabauraud’s dextrose agar at 28°C. The monthly counts of keratinophilic fungi showed irregular fluctuations, with a peak in April and the lowest point in November. Dermatophytes and closely related fungi were represented by Aphanoascus fulvescens, Aphanoascus sp., Chrysosporium lucknowense, Gymnoascus uncinatus, and Trichophyton rubrum. In conclusion, the study reports the incidences of some dermatophytes found in the floor dust of student houses of South Valley University, Egypt.     

Occurrence of keratinophilic fungi on Indian birds

Keratinophilic fungi were isolated from feathers of most common Indian birds,viz. domestic chicken (Gallus domesticus), domestic pigeon (Columba livia), house sparrow (Passer domesticus), house crow (Corvus splendens), duck (Anas sp.), rose-ringed parakeet (Psittacula krameri). Out of 87 birds, 58 yielded 4 keratinophilic fungal genera representing 13 fungal species and one sterile mycelium. The isolated fungi were cultured on Sabouraud's dextrose agar at 28±2°C.Chrysosporium species were isolated on most of the birds.Chrysosporium lucknowense andChrysosporium tropicum were the most common fungal species associated with these Indian birds. Maximum occurrence of fungi (47%) was recorded on domestic chickens and the least number of keratinophilic fungi was isolated from the domestic pigeon and duck. The average number of fungi per bird was found to be the 0.44.     

Isolation of keratinophilic fungi from the floor dust of Arab kindergarten schools in the West Bank of Jordan

The keratinophilic mycoflora of floor dust of seventy two classrooms in 24 kindergarten schools (children aged 2–5) in the city of Nablus was studied using a hair-baiting technique. The study was aimed at the evaluation of extent of diffusion of keratinophilic fungi in this environment in relation to human presence and the age of children in order to determine their role and impact in the epidemiology of human dermatophytoses. Thirty three species were isolated. A large proportion of these species are either well-known human and animal mycotic agents or have been isolated frequently from human and animal lesions. These pathogenic and potentially pathogenic fungi comprised about 85.8% of all keratinophilic fungal isolates found in the classroom dust.The results of this investigation have also been discussed in respect to previous studies on human dermatophytoses in the West Bank of Jordan.     

Incidence of dermatophytes and cyclohexamide resistantfungi on healthy children hairs and nails in nurseries

In order to estimate the prevalence of dermatophytes and other fungi on healthy children hairs and nails, 92 hair samples and 85 nail samples (groups of 10 finger nails from each child) were collected from 5 nurseries (children aged 9 months up to 4 years) in Assiut city. From hair samples 22 species were collected, Trichophyton (2 species) and Microsporum (2 species) were the only recovered dermatophytes in addition to well known keratinophilic genus Chrysosporium (4 species). From nail samples, 18 species were identified, Trichophyton was represented by 4 species, Microsporum, 2 species and Chrysosporium, 4 species. Also, several other saprophytes and cycloheximide resistant fungi were isolated. This revised version was published online in June 2006 with corrections to the Cover Date.     

Keratinophilic fungi on sheep hairs from the West Bank of Jordan

The mycoflora of the hair in 285 sheep from the West Bank of Jordan was analysed and the frequency of occurrence and the relative importance value for different fungal species found were calculated. Ninenty six species which belong to 36 genera were isolated. Forty one of these species were either well-known agents of animal and human mycoses (Trichophyton verrucosum, T. mentagrophytes, Microsporum nanum, M. canis, and others), or have been isolated from human and animal lesions (Arthroderma cuniculi, A. curreyi, Chrysosporium tropicum, Acremonium kiliense, Aphanoascus fulvuscens, Aspergillus versicolor, Paecilomyces lilacinus, Scopulariopsis brevicaulis, and others). These pathogenic fungi comprised 75.4% of all fungi recovered from the hair of sheep. This animal seems to represent an adequate reservoir for several dermatophytes and several potentially pathogenic fungi.