Bacteria - Worst Item in House for Germs and How to Stop

We often think that the bathroom is the place that harbors the most bacteria. However, according to microbiologist Charles Gerba at the University of Arizona, Tucson, the kitchen sponge is the germiest item in the home, containing on average 7 billion bacteria (J. Brown, "Food Safe News," Colorado State University, Vol IX, No 4, 2005).

Wiping surfaces with a contaminated sponge spreads bacteria. A wet sponge serves as a "reservoir and vehicle for food-borne pathogens to cause illness," and E. coli and fecal coliforms were found in 33-67% of sponges in a study of kitchens in the US (Manan, Eastridge, & Mudd, "Effective household disinfection methods of kitchen sponges," USDA-ARS, 2007).

Manan, et. al. examined several methods to disinfect sponges and concluded that placing sponges in the microwave (one minute) or dishwasher were the most effective, killing 99.99% of bacteria, yeasts and molds compared to soaking in bleach solution, lemon juice, deionized water, or left untreated.

3 SIMPLE WAYS TO STOP BACTERIA GROWTH ON SPONGE

To sanitize a sponge, below are three simple ways to stop bacteria growth.

1. LET DRY: NEVER leave a wet sponge laying around. A moist sponge is a breeding ground for bacteria. After each use, clean sponge, rinse well, ring out, and let dry.

2. MICROWAVE (only for sponges that contain no metal): At least once a week, put a damp sponge on a paper towel in the microwave for 60 seconds. SPONGE MUST BE WET or it could catch fire. LET COOL DOWN in microwave before handling.

3. DISHWASHER: put the sponge in the dishwasher with a heated drying cycle every time you run the dishwasher.

If the sponge is smelly, then there is too much bacteria, mold, or mildew in the sponge and the methods above may not remove the odor. It's best to throw out the smelly sponge and get a new one.

For more information, go to:

http://www.ext.colostate.edu/safefood/newsltr/05summer.pdf

http://naldc.nal.usda.gov/download/23351/PDF