Danger Zone: The Kitchen Sponge

kitchen_sponge
Kitchen Sponge, Public Domain, 2006

Your kitchen sponge is very likely the most contaminated object in your home. This is not news. What is news is the research reporting that trying to decontaminate it might result in allowing the proliferation of dangerous bacteria.

Regular cleaning of sponges, indicated by their users, significantly affected the microbiome structure. … Our study stresses and visualizes the role of kitchen sponges as microbiological hot spots in the BE (note: background environment), with the capability to collect and spread bacteria with a probable pathogenic potential.

Microbiome analysis and confocal microscopy of used kitchen sponges reveal massive colonization by Acinetobacter, Moraxella and Chryseobacterium species
Nature, July 2017

The New York Times picked up on this Nature research article and discussed it twice.

Stop. Drop the sponge and step away from the microwave.

That squishy cleaning apparatus is a microscopic universe, teeming with countless bacteria. Some people may think that microwaving a sponge kills its tiny residents, but they are only partly right. It may nuke the weak ones, but the strongest, smelliest and potentially pathogenic bacteria will survive.

Cleaning a Dirty Sponge Only Helps Its Worst Bacteria, Study Says
New York Times, Aug. 4, 2017, by Joanna Klein

The second New York Times article is worth reading. The author talks again with researchers whose paper was published last month in Nature, along with a several other experts in the world of food safety. The gist of the recommendations is that sponges are very difficult to clean well. If they start to smell, discard them. A Norwegian microbiologist recommends replacing them on the daily basis if someone in the house has cancer. The people most vulnerable to pathogens are infants, the elderly, and anyone with a compromised immune system. I’m sure we haven’t heard the last of this!