Epidemiologic Study of Opportunistic Fungi Contaminating Soil of Schools, Mosques and Hotels in Diwaniya City - Iraq

Abstract

Soil mycoflora in several schools, mosques and hotels in Diwaniya city were examined using dilution plate technique and three different culture media with and without supplementation of cycloheximide antifungal. A total number of fungal isolates observed in all experiments were 2589 that represent 57 species related to 48 genus, in addition to the white and dark sterile mycelium. Cycloheximide substantially affected the frequency of isolated fungi. Where Penicillium chrysogenum was the most frequent species (44.73%) on culture media free from cycloheximide. Acremonium kiliense was the most with more capability than other examined fungi in tested blood which took 3 days only while this ability of other species was varied from 4 to 12 days . frequent one (26.85%) on media supplemented with this antifungal. In contrast the frequency and occurrence of P. chrysogenum in both soils of school (41.26%) and (95.95%) respectively and of mosques (43.63%) and(100%) respectively was higher than other species, also this species was the most occurring (90%) in hotels soil. Memoneilla subimplex was the most frequent species (18.87%) in this soil. Number of isolates were varied according to the addition of cycloheximide and the composition of culture media: highest number of fungal isolates (337) were recorded when potato dextrose agar used, in contrast the greatest numbers of fungal species (21) were identified when sabouraude dextrose agar was used. In culture media free of cycloheximide the number of fungal isolates and fungal species were substantially increased to 720 and 37 respectively. The results of this experiment revealed a negative correlation between soil fungi and pH ( as r= 0.307 with fungal isolates and 0.185 with the number of fungal species ) while this correlation was positive with organic content of soil salinity (r= 0.042 and 0.130 with fungal isolates and fungal species respectively ) moreover the results showed negative correlation between fungal isolates and soil salinity (r=0.202) while the number of species of fungal society was positively correlated ( r= 0.109). The hemolytic activity of 30 species in vitro using blood agar culture:18 species showed variable capabilities in hemolysis. Aspergillus fumigatus was