How much bacteria can a sponge spread around a kitchen?by Greg Harbaugh on 06/10/14
The answer is; it depends. In a home kitchen the sponge is a major culprit in moving bacteria from surface to surface. It's supposed to be a cleaning tool, but most people only clean and sanitize their sponge after hearing of an outbreak of salmonella on the evening news.
The normal cleaning procedure after putting the dishes in the dishwasher is to wring out the sponge or dish cloth with kinda warm water and wipe the table and counter. The result is moving bacteria from surface to surface. 100 F water doesn't kill anything. The counter may look better, but under a microscope it would be scary.
At a minimum clean your counters with warm soapy water, rinse with clear water, and let them air dry. Throw your damp sponge in the microwave for a minute to kill the bugs or better yet, throw the sponge away and wipe with a disposable towel.
Sponges are the salmonella suite.