Biomedical subjects
Publications and source records attributed to A H Moubasher.
The causative dermatophytic species of tinea capitis were identified in 91 patients in Qatar. Microsporum canis was the most common isolated organism (86.81%) followed by Microsporum ferrugineum and Trichophyton violaceum. A gray patch type of tinea capitis was the predominant presentation (87.91%), and the disease was more prevalent among Qatari boys.
107 species and 8 species varieties belonging to 44 genera were collected from combine harvester wheat and sorghum dusts (35 genera and 91 species + 4 varieties) and from the atmosphere of their hay sites (26 genera and 69 species + 4 varieties) on glucose- and cellulose-Czapek's Dox agar at 28 degrees C and 45 degrees C. The mycoflora of wheat and sorghum dusts were basically similar on the two types of media and the most common fungi were: Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. ochraceus, A. sydowii, A. terreus, Cochliobolus spicifer, Emericella nidulans, Fusarium moniliforme, Penicillium chrysogenum, P. duclauxii, P. funiculosum and P. oxalicum. Truly thermophilic species were frequently encountered from the two substrates: Chaetomium thermophilum, Humicola grisea var. thermoidae, H. insolens, Malbranchea pulchella var., sulphurea, Rhizomucor pusillus, Sporotrichum thermophilum, Talaromyces thermophilus, Thermoascus thermophilus and Thermomyces lanuginosus. The airborne fungi in the two atmospheres were basically similar and the most prevalent species were members of Alternaria (1 species), Aspergillus (18 species + 2 varieties), Chaetomium (2 species), Cochliobolus(3 species), Emericella (3 species + 2 varieties), Fusarium (3 species), Mucor (1 species), Penicillium (14 species) and Stachybotrys (1 species).
Three methods were used for the isolation of fungi in the present investigation: the dilution-plate method, hair-baiting technique with horse hairs and the "exposed plate" method. Sabouraud's glucose agar at 28 degrees C was also used as isolation medium. 102 species and 2 species varieties belonging to 36 genera were collected from combine harvester wheat and sorghum dusts and from the atmosphere of hay or winnow sites. Chrysosporium was represented by 6 species: C. asperatum, C. indicum, C. keratinophilum, C. merdarium, C. pannorum and C. tropicum. Several filamentous fungi tolerating high levels of cycloheximide and other moulds were frequently encountered in the two types of dusts and in the two atmospheres, such as members of Acremonium, Alternaria, Aspergillus, Cladosporium, Emericella, Eupenicillium, Fusarium, Paecilomyces, Penicillium, Piedraia, Rhizopus, Scopulariopsis and others.
One-hundred and eleven species and three species varieties belonging to 39 genera were collected from 50 dust samples on the five media used at 28 degrees C. Using the hair-baiting technique with horse hair, 10 species of Chrysosporium were isolated: C. asperatum, C. state of Arthroderma tuberculatum, C. indicum, C. inops, C. keratinophilum, C. merdarium, C. pannorum, C. queenslandicum, C. tropicum and C. xerophilum. True dermatophytes were isolated: Trichophyton verrucosum and Trichophyton sp. Also, numerous fungi tolerating high levels of cycloheximide were encountered, such as members of Acremonium, Aspergillus and Penicillium. On plates of glucose or cellulose Czapek-Dox agar (free from sucrose) the most frequent fungi were: Alternaria alternata, Aspergillus flavus, A. flavus var. columnaris, A. fumigatus, A. niger, A. ochraceus, A. sydowii, A. terreus, Chaetomium globosum, Cladosporium herbarum, Emericella nidulans, Fusarium oxysporum, Mucor hiemalis, Penicillium chrysogenum, P. oxalicum, Scopulariopsis brevicaulis and Ulocladium atrum. On plates of 50% sucrose or 10 and 20% NaCl-Czapek's agar, some interesting species were frequently encountered: Eurotium amstelodami, E. chevalieri, E. halophilicum, E. montevidensis, E. repens, E. rubrum and Scopulariopsis halophilica. The isolated fungi have been tested for osmophilicity and halophilicity, they showed different rates of growth on sucrose and sodium chloride-Czapek's medium of various osmotic potential.
The frequency of occurrence of keratinolytic fungi in seventy soil samples collected from different sites in Upper Egypt and in the coastal area of the Mediterranean and baited with human and animal hair and pigeon feathers was determined. Twenty-one species in addition to an unidentified species, which belong to sixteen genera were collected. Chrysosporium indicum, B. tropicum, C. keratinophilum and Microsporum gypseum were the most frequent fungal species recovered from baited soils. The eight soil samples collected from the salt marshes of the coastal Mediterranean area were completely free from any keratinolytic fungi, whereas the sixty-two soil samples collected from cultivated soils contributed a species ranging from one to four species.
The seasonal fluctuations of aquatic fungi were studied over 24 water sample collected monthly between May 1979 and April 1981 from the River Nile near Assiut (about 375 km, south from Cairo, Egypt). The richest periods in aquatic fungal genera and species were September--December 1979, January--March, October--December 1980, and January--April 1981. These periods represent low or moderate temperature months. The poorest periods were May--August 1979, April, May, July, August and September 1980 which are almost summer months. Twenty-nine species and one variety of Olpidiopsis saprolegniae which belong to ten genera of aquatic fungi were collected during this investigation. Three genera were of high seasonal occurrence (19-24 months) namely: Achlya, Saprolegnia and Dictyuchus. Three other genera were of moderate seasonal occurrence (6-11 months) namely: Isoachlya, Leptolegnia and Pythium. The rest of genera were of low or rare seasonal occurrence.
The air-borne fungi displayed diurnal periodicities. The total count of fungi exhibited double-peaked pattern, one at 6 a.m. and the other at 18 p.m. (the higher). Aspergillus diurnal activities were almost parallel to those of total fungi. Cladosporium showed on main peak at 18 p.m. Penicillium and Alternaria displayed some pattern of diurnal activity and their maxima were observed.
73 species which belong to 24 genera were collected in 200 and 35 exposures made during the period May 1976-October 1977 at each of two levels (2 m and 20 m). The air-borne fungi showed seasonal periodicities and the highest incidence was recovered in spring and autumn and the least in the summer. Aspergillus was the dominating genus. 17 species were collected at the two levels of which A. niger and A. flavus were the most common. Other common genera were Cladosporium which was represented by C. herbarum, C. cladosporioides, C. sphaerospermum, and C. macrocarpum. 7 species of Curvularia were identified of which C. pallescens was the most frequent at the low and C. spicifera at the high level. Drechslera was represented by 6 species of which D. halodes was the most common at the two levels. Only one Alternaria species, A. alternata was isolated at both levels. 10 Penicillium were recovered, P. notatum was the most frequently one isolated at the two levels. Many fungal spore showers of Cladosporium, Aspergillus, Curvularia, and Alternaria were recorded during the experimental period.
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In the early periods of soil storage, the total number of fungi almost regularly and significantly increased with the concentration of keratinaceous material (ground buffalo hooves) between 1% and 10%. A concentration of 20% was stimulative after 7 days and became toxic after 15 days and remained so through the end of the experiment. With increase in the storage period, the beneficial effect of all concentrations was lost and in the case of high concentrations (5-20%) toxic ammonia was produced. The occurrence of Scopulariopsis brevicaulis, Cephalosporium acremonium, Chrysosporium tropicum, C. indicum, and C. keratinophilum increased markedly, especially at the higher concentrations of the keratinaceous material and after long periods of incubation. With increase in the concentration of keratinaceous material, the rate of evolution of ammonia from the soil sharply increased during the second week after treatment and fell off sharply during the third and fourth weeks. In soil stored at 35 C, the rate of decline in total fungi after longer periods of incubation was sharper at 35 C than at 25 C. Also the amount of evolved ammonia during the first and the second weeks was almost always higher at 35 C than at 25 C. Fourteen species were tested for keratinolytic activity. Three of them were highly keratinolytic and five moderately so.
To evaluate the potential for mycotoxin production by fungi contaminating blue-veined cheese, as well as by the ripening fungus, Penicillium roqueforti, the fungal flora of six of local and imported brands was determined. A total of 19 fungi were isolated from the six brands tested. Fourteen of the isolates were toxic to chicken embryos. The toxigenic fungi produced the following mycotoxins: Aspergillus fumigatus, kojic acid; A. versicolor, sterigmatocystin; Penicillium roqueforti, penicillic acid and unidentified toxic metabolites.
Ninety-five species and seven varieties which belong to thirty-nine genera were isolated from 74 soil samples from salt marshes. At 28 degrees C, on 30% sucrose Czapek's agar, ninety species and four varieties which belong to thirty-six genera were encountered, from which A. niger, A. fumigatus A. terreus and P. notatum were the most frequent. On 60% sucrose Czapek's agar, sixty-three species and three varieties were recovered which belong to twenty-five genera, from which A. niger, A. fumigatus, Cladosporium herbarum and A. terreus were the most frequent. At 45 degrees C, on 30% sucrose, sixteen species and four varieties were identified but on 60% sucrose, fourteen species and three varieties were isolated. A fumigatus and A. niger were the most frequent on both sucrose concentrations. The results reveal that the soil samples poor in total osmophilic fungi (at 28 degrees C) were significantly higher in their content of total soluble salts, Na and K and significantly lower in the average number of species per soil samples than the rich ones; the difference was non-significant in case of organic matter.
45 cultures of Aspergillus, belonging to 25 species isolated from different sources in Egypt, were tested for toxicity to chicken embryos and to Bacillus megaterium growth. Mycotoxins were detected by TLC analysis. 30 isolates out of 45 exhibited toxicity. 3 isolates were recorded as high-toxin producers. (A. egyptiacus, A. carneus and A. terricola). The 2 former produced unknown toxins, while A. terricola produced aflatoxins (B1, B2, G1 and G2). Aflatoxins production by A. terricola is reported for the first time.
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