Dishwashers as a reservoir of opportunistic fungal pathogens: a case study of appliances in Lower Silesia (SW Poland).

Dishwashers may serve as reservoirs of microorganisms. In this study, 22 dishwashers from Lower Silesia (Poland) were analyzed for fungal contamination. Samples collected from various dishwasher sites revealed the presence of yeast-like fungi, with rubber seals being the most frequently colonized site. Fungal species were identified using classical and molecular methods, including LSU gene sequencing. The most frequently isolated species were Exophiala dermatitidis, followed by Candida parapsilosis and Magnusiomyces spp. No clear correlations were observed between the various dishwasher features (model, usage time, frequency of use/sanitizing, operating temperature, number of users) and fungal contamination. Most of the isolated species are considered human opportunistic pathogens, highlighting the importance of monitoring household environments.