An-Najah Staff

Floor dust collected from classrooms of thirty three elementary schools (16 for girls, and 17 for boys) (children aged 6–11), and twenty four preparatory schools (13 for girls, and 11 for boys) (children aged 12–14) was studied for the occurrence of keratinophilic fungi with respect to human presence and age of children. Tichophyton mentagrophytes was present in 15.4% of the preparatory schools for girls, in 12.5% of elementary schools for girls, and in 11.8% of elementary schools for boys. It was not found in preparatory schools for boys. Microsporum gypseum was found in preparatory schools for girls only (7.7%). Trichophyton terrestre was also only isolated from elementary schools for boys (5.9%). Chrysosporium species were present in 30.3% of all elementary schools (10 schools/33), and in 20.8% of all preparatory schools (5 schools/24). Geotrichum candidum was the most frequent and predominant keratinophilic species in all schools. Pathogenic and potentially pathogenic keratinophilic fungi comprised a large proportion of all fungal isolates recovered from all schools ; they comprised 87.2 %–89.5 % of all fungal isolates in the elementary schools, and 90.4%–93.5% of all fungal isolates in preparatory schools.

Raw city sewage irrigation seems to affect population densities of keratinophilic fungal communities, with the highest population densities being found in the heavily polluted field soils, while the lowest population densities occur in non-polluted field soils. However, basic similarities in the biodiversity of keratinophilic fungal communities exist in both non-polluted and polluted field soils and raw city sewage. Comparable numbers of fungal species exist in these habitats, and the species most commonly found include Alternaria alternata, Aspergillus candidus, Geotrichum candidum, and Paecilomyces lilacinus. Field soils receiving either raw city sewage or normal irrigation water were shown to be rich in pathogenic and potentially pathogenic keratinophilic fungi, including dermatophytes, with raw city sewage yielding the highest percentage, followed by moderately polluted fields, non-polluted fields, and heavily polluted fields. Dermatophytes and their related fungi recovered from these habitats include Microsporum gypseum, Trichophyton ajelloi, Arthroderma cuniculi, A. curreyi, Chrysosporium keratinophilum, C. tropicum and C. pannorum. The ability of 55 cycloheximide-resistant fungal species (117 isolates) to degrade human hair in vitro was investigated. The species were recovered from polluted (raw city wastewater-irrigation) and non-polluted (normal irrigation) field soils and raw city wastewater. The intensity of keratinolytic activity (IKA) was estimated on a scale of 0-100, based on morphological expression of keratinolysis. A high percentage of the species tested (48/55, 87%) demonstrated a varying degree of keratinolytic activity. Five species ( Chrysosporium keratinophilum, Microsporum gypseum, Penicillium frequentans, Rhizopus stolonifer, and Trichophyton ajelloi) showed strong IKA, and were capable of producing invasive structures related to radial penetration and surface erosion contemporaneously. On the other hand, seven of all the tested species, including Acremonium species, Aspergillus carneus, Nectria inventa, Penicillium citrinum, Paecilomyces variotii, Plectosphaerella cucumerina, and Verticillium nubilum, showed no keratinolytic activity. The keratinolytic activity of the following species is recorded in this study for the first time: Acremonium strictum, Chrysosporium pannorum, Cladosporium herbarum, Fusarium tricinctum, Gliocladium viride, Humicola fuscoatra var. fuscoatra, Nectria ventricosa, Penicillium griseofulvum, P. islandicum, Verticillium catenulatum, and V. psalliotae. Isolates of the same species can vary in their IKAs. Thus, such a characteristic does not seem to be constant or speciesspecific.

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 wastewater 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. Wastewater 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.

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).

The aqueous extracts (15 micrograms ml-1 medium) of 22 plants used in folkloric medicine in Palestine were investigated for their antifungal activity and minimum inhibitory concentrations (MICs) against nine isolates of Microsporum canis, Trichophyton mentagrophytes and Trichophyton violaceum. The extract of the different plant species reduced colony growth of the three dermatophytes by 36 to 100% compared with the control treatment. Antimycotic activity of the extract against the three dermatophytes varied significantly (P < 0.05) between test plants. Extracts of Capparis spinosa and Juglans regia completely prevented growth of M. canis and T. violaceum. The most active extracts (90-100% inhibition) were those of Anagallis arvensis, C. spinosa, J. regia, Pistacia lentiscus and Ruta chalapensis against M. canis; Inula viscosa, J. regia and P. lentiscus against T. mentagrophytes; and Asphodelus luteus, A. arvensis, C. spinosa, Clematis cirrhosa, I. viscosa, J. regia, P. lentiscus, Plumbago europea, Ruscus aculeatus, Retema raetam and Salvia fruticosa against T. violaceum. The MICs of these most active plants ranged from 0.6 to 40 micrograms ml-1. The three dermatophytes differed significantly with regard to their susceptibility to plant extracts. Trichophyton violaceum was the most susceptible being completely inhibited by 50% of the extracts followed by M. canis and T. mentagrophytes which were completely inhibited by only 23 and 14% of the extracts, respectively.