Comparison of fungi found in bathrooms and sinks.

To identify the pathogenic fungi present in bathrooms, the growth of fungi collected from the drains of bathrooms was studied at various temperatures and compared with that of fungi from kitchen sink drains. Only a small number of fungi from bathrooms and sinks grew on media incubated at 37 degrees C, at which temperature the fungal count was about 1/600 of that at 25 degrees C. Although hot water is used more frequently in bathrooms than in sinks, the fungal counts at 37 degrees C were similar for bathrooms and sinks. Five species of fungus that can grow at 37 degrees C and were found to grow prolifically in bathrooms were identified using DNA and morphological analysis. In both bathrooms and sinks, Exophiala dermatitidis was predominant in culture at 37 degrees C. Moreover, E. dermatitidis grew at 40 degrees C and used surfactant as a nutrient. Thermotolerant fungi appear to inhabit bathrooms and all residential water appliances.