Characteristics of Recent Fungal Contamination in Bathrooms

The fungal flora of bathrooms was examined using a modified medium. PDA medium consisting to one-fourth of nutrient was used for detecting fungi. This low-nutrient medium was thought to be convenient for detecting slowgrowing fungi while suppressing fast-growing yeast. Heavy fungal contamination was found on toys, soap dishes, and in the drain mouth. Characteristic mold genera in the bathrooms were Exophiala, Cladophialophora, Phoma and Scolecobasidium, which, in contrast to elsewhere, were more predominant than Cladosporium and Acremonium inside bathrooms. Cladophialophora in particular is not common in indoor environments, and the specimen was identified using genetic data. Of the yeasts, Rhodotorula was predominant in all areas of the bathroom. Molds characteristically found in bathrooms were similar to those found inside washing machine using detergent. Exophiala, Phoma, Cladophialophora and Scolecobasidium were also predominant in the lower areas and in unit-type bathrooms. In contrast, Cladosporium and Aureobasidium were predominant in the upper areas of the bathroom in all seasons and seemed to use glycerides derived from human skin as nutrient. Also discussed are factors affecting the differing distribution of Cladosporium, Exophiala, and other molds.