According to a study by the Institute for Precision Medicine (IPM) at the University of Furtwangen, Villingen-Schwenningen, Germany, the kitchen sponge harbors an abundant bacterial community and, in some cases, pathogenic, as close relatives of bacteria that they cause pneumonia and meningitis .
Worse than the bathroom
Campylobacter, Enterobacter cloacae, Escherichia coli, Klebsiella Proteus, Salmonella, and Staphylococcus, among others, are found in high concentrations in kitchen sponge. Such bacterial densities, the researchers say, are only found in feces .
Kitchen sponges have the second highest coliform load in the entire home, after drains. The researchers made the discovery by sequencing the microbial DNA of 14 kitchen sponges used on the structure of the microbiome .
The problem, according to these researchers, is that trying to wash the sponge makes the problem worse. During the study, no single method was able to achieve an overall bacterial reduction of more than approximately 60%. In fact, surprisingly, boiling or microwaving the sponges did not kill these microbes: sponges that had been regularly sanitized were filled with a higher percentage of pathogen-related bacteria than sponges that had never been cleaned. The only solution to keep bacteria to a minimum in the kitchen, experts say, is to replace the kitchen sponge every week .