Distribution of Fungi and Actinomycetes in the Soil of Different Regions of Sari and Its Suburbs)2002)

Introduction: The fungi are found in the soil of all the world. The prevalence  in each area depends on environmental and nutritional conditions. Considering the importance of soil in transmission of diseases, this study was conducted to determine the prevalence of fungi and actinomycetes in the soil of different regions of Sari and its suburbs in 2002.

Materials and Methods: In a descriptive study, 160 samples from superficial layers of soil of different regions of Sari and its suburbs were obtained. The homogenous suspensions that were prepared by flotation, were cultured in the routine media for isolation of the saprophytic and dermatophytic fungi.  The keratinophilic fungi and actinomycetes were isolated by keratin bait and antibiotic dilution methods, respectively. The species of the saprophytic and dermatophytic fungi were determined by macroscopic and microscopic examintions and physiological tests. By employing disk diffusion test, susceptibility to six different dyes was used for the differentiation of yeasts. The data were analyzed by descriptive statistics. 

Results: 20200 colonies were isolated which belonged to 297 species from 46 different genera. The forest soil samples contained the most different varieties & numbers of species (15.4%). Most of  the isolated geophilic dermatophytes and keratinophilic fungi were from the soil  near the animal’s nests, forest and street side soils. The most common keratinophilic fungi were chrysosporium and the most common geophilic dermatophytes were M. gypseum, T. ajelloi and T. terrestre, respectively. The highest rate of isolated aerobic actinomycetes belonged to street side and forest soil and then the soil adjacent to animal’s nest and the most common isolated species were Nocardia asrteroides. Most of the isolated yeasts from seacoast, street side and farmlands were Geotrichum candidum. The highest percentage of the isolated saprophytic fungi was from forest soil and the most common saprophytic fungus was penicillium. 

Conclusion: Considering the fact that  most of  the potential pathogenic fungi were isolated from the forest and animal’s nest soils, it seems that at the time of direct contact with soil, the preventive measurements to control infection are suggested. Also further similar studies in different areas and climatic conditions are recommended.