BLOOMINGTON, IND.—A new study published in the British journal Fungal Biology reports that potentially pathogenic fungi including a type of “black yeast” are now able to live in extreme conditions such as in dishwashers.* According to researchers, these same pathogens may also be found in other appliances such as washing machines and coffee makers because all can provide a moist environment in which the pathogens can grow.
The study, which involved private homes located in 101 cities on six continents, also reported:
• The fungi were found on the rubber seal that lines the inside of the door on 62 percent of dishwashers.
• In 56 percent of those dishwashers, Exophiala dermatitidis and E. phaeomuriformis accommodated the fungi. These are types of black yeast that can harm the central nervous system.
• The fungi appeared to be tolerant to heat, cleaning detergents, and both acid and alkaline water.
“This is a combination of extreme properties not previously observed before in fungi,” reported the researchers who conducted the study. “The invasion of these [pathogens] into our homes represent[s] a potentially serious health risk.”
Stephen Ashkin, president of The Ashkin Group and a longtime advocate for green cleaning, views the study with possible foreboding for the professional cleaning industry.
“It suggests that these pathogens and likely others are evolving, becoming resilient to the chemicals we have used in the past to eradicate them,” Ashkin says. [I hope that], instead of developing even more powerful chemicals that can harm the environment, we [will] develop new cleaning strategies that are just as effective but have less [negative] impact on the environment.”
*P. Zalar, M. Novak, G.S. de Hoog, and N. Gunde-Cimerman, “Dishwashers—A man-made ecological niche accommodating human opportunistic fungal pathogens,” Fungal Biology, June 2011.
