'My dishwasher is trying to kill me': New research finds harmful fungal pathogens living in dishwasher seals

June 20, 2011, Elsevier

A potentially pathogenic fungus has found a home living in extreme conditions in some of the most common household appliances, researchers have found. A new paper published in the British Mycological Society journal, Fungal Biology, published by Elsevier, shows that these sites make perfect habitats for extremotolerant fungi (which includes black yeasts). Some of these are potentially dangerous to human health.

Modern living comes with an increasing need for electrical household equipment such as dishwashers, washing machines and coffee machines. A characteristic of these appliances is a moist and hot environment. In the case of dishwashers, between 60º to 80ºC are intermittently produced and aggressive detergents and high concentrations of salt are used in each washing cycle.

The article focuses on the occurrence of potentially pathogenic fungal flora located in dishwashers, over a sample of private homes from 101 cities on 6 continents. 62% of the dishwashers contained on the rubber band in door, 56% of which accommodated the polyextremotolerant black yeasts Exophiala dermatitidis and E. phaeomuriformis. Both Exophiala species showed remarkable tolerance to heat, high salt concentrations, aggressive detergents, and to both acid and alkaline water. This is a combination of extreme properties not previously observed in fungi.

Exophiala dermatitidis is rarely isolated from nature, but is frequently encountered as an agent of human disease, both in compromised and healthy people. It is also known to be involved in pulmonary colonization of patients with cystic fibrosis, and also occasionally causes fatal infections in healthy humans. The invasion of black yeasts into our homes represents a potential health risk.

The discovery of this widespread presence of extremophilic fungi in some of our common suggests that these organisms have embarked on an extraordinary evolutionary process that could pose a significant risk to human health in the future.

Explore further: Scientists discover a master key to microbes' pathogenic lifestyles

More information: P. Zalar, M. Novak, G.S. de Hoog, N. Gunde-Cimerman, Dishwashers - A man-made ecological niche accommodating human opportunistic fungal pathogens, Fungal Biology, In Press, Corrected Proof, ISSN 1878-6146, DOI: 10.1016/j.funbio.2011.04.007

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5 / 5 (4) Jun 20, 2011
And now for the shock.

Walk into almost any restaurant kitchen and look at the seals/gaskets on any cooler/walk-in. They are 99% of the time absolutely disgusting, they are oft one of the least cleaned area in any kitchen, yet most health inspectors still take a lackadaisical stance towards it. I'm one of the only chefs I know that requires cooks to clean them on a regular basis.

Oh...the things I've seen, the things I've seen...*holds head and weeps*
not rated yet Jun 20, 2011
OK. What should we do to minimize the risk of infection?

Let the dishwasher dry up after each use? Would it help?

What else?
5 / 5 (1) Jun 20, 2011
Hmm, go back to good old fashioned washing up in the sink perhaps?
5 / 5 (1) Jun 20, 2011
OK. What should we do to minimize the risk of infection?

Let the dishwasher dry up after each use? Would it help?

What else?

Nope, just get a blunt blade like a butter knife, wrap a wrag soaked in soapy bleach-water around the tip, and go to work, get all the grooves clean.

And Peteri has it right lol. How lazy have we become ?

I really wonder how the hell people are so messy that they get food build-up in their dishwasher gaskets tho', that's downright scary. Are they throwing the dishes into the dishwasher ?
not rated yet Jun 21, 2011
Wash dishes manually in a sink, problem solved!
not rated yet Jun 21, 2011
A dishwasher uses much less water than hand washing is the main reason I use a dishwasher, not lazyness. And further, if you are prewashing your dishes before putting them in the dishwasher you are negating the benefits of using one. I think wiping down the seals and leaving the door open after use is a probably the best way to go. I have to do the same thing on my front loader washer and my fridge so it is not hard to add to my routine.
not rated yet Jun 21, 2011
'My dishwasher is trying to kill me': New research finds harmful fungal pathogens living in dishwasher seals

Try clubbing them.

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