Distribution of dermatophytes from soils of urban and rural areas of cities of Paraiba State, Brazil.

The dermatophytes, keratinophilic fungi, represent important microorganisms of the soil microbiota, where there are cosmopolitan species and others with restricted geographic distribution. The aim of this study was to broaden the knowledge about the presence of dermatophytes in soils of urban (empty lots, schools, slums, squares, beaches and homes) and rural areas and about the evolution of their prevalence in soils of varying pH in cities of the four mesoregions of Paraiba State, Brazil. Soil samples were collected from 31 cities of Paraiba State. Of 212 samples, 62% showed fungal growth, particularly those from the Mata Paraibana mesoregion (43.5%), which has a tropical climate, hot and humid. Soil pH varied from 4.65 to 9.06, with 71% of the growth of dermatophytes occurring at alkaline pH (7.02 - 9.06) (ρ = 0.000). Of 131 strains isolated, 57.3% were geophilic species, particularly Trichophyton terrestre (31.3%) and Mycrosporum gypseum (21.4%). M. nanum and T. ajelloi were isolated for the first time in Paraiba State. The zoophilic species identified were T. mentagrophytes var. mentagrophytes (31.3 %) and T. verrucosum (7.6 %), and T. tonsurans was isolated as an anthropophilic species. The soils of urban areas including empty lots, schools, slums and squares of cities in the mesoregions of Paraiba State were found to be the most suitable reservoirs for almost all dermatophytes; their growth may have been influenced by environmental factors, soils with residues of human and/or animal keratin and alkaline pH.