Harmful germs found in dishwashers

Dishwashers may be the perfect breeding ground for potentially harmful germs, a study has found.

The high temperatures and moist environment found in dishwashers provide perfect habitats for two types of potentially harmful fungi.

Researchers took samples from dishwashers in 189 homes located in 101 cities on six continents.

Sixty-two per cent of dishwashers sampled contained the fungi Exophiala dermatitidis and E. phaeomuriformis on the rubber band in the appliance door.

The Exophiala showed "remarkable tolerance" to heat, high salt concentrations, harsh detergents, and to both acid and alkaline water, the researchers said.

Both species, which are types of black yeast, are known to cause disease in humans, and can colonise the lungs of patients with cystic fibrosis.

The researchers, from the University of Ljubljana, Slovenia, said the presence of black yeasts in homes represented a potential health risk.

In the journal Fungal Biology, they wrote: "The discovery of this widespread presence of extremophilic fungi in some of our common household appliances suggests these organisms have embarked on an extraordinary evolutionary process that could pose a significant risk to human health in future."

This article was published on Wed 22 June 2011