Kitchen sponges, due to their porous nature and water soaking ability, function as ideal incubators for microorganisms. Specifically, from close relatives of the bacteria that cause pneumonia and meningitis, according to a study by the Institute for Precision Medicine (IPM) at the University of Furtwangen, Villingen-Schwenningen, in Germany.
This element so common in all kitchens and so related to domestic hygiene contains huge amounts of bacteria such as Campylobacter , Enterobacter cloacae , Escherichia coli , Klebsiella Proteus , Salmonell a and Staphylococcus . Also, Moraxella osloensis can cause infections in people with weak immune systems . According to the research, published in the journal Scientific Reports , a single cubic centimeter could be teeming with bacteria, which corresponds to around seven times the number of people on Earth. Such bacterial densities, scientists say, are only found in feces. The study showed that kitchen environments receive more microbes than toilets, although less than drains. Thus, kitchen sponges have the second highest coliform load in the whole house, after drains.
The researchers made the discovery by sequencing the microbial DNA of 14 kitchen sponges used on the structure of the microbiome. Furthermore, it was intended to estimate the pathogenic potential of the spongy microbiota. Finally, the spatial distribution pattern of bacteria in the kitchen sponge tissue was explored by 3D microscopy.
How to get rid of bacteria?
It seems that washing our kitchen scrubber not only doesn’t fix the problem, it makes it 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 didn’t 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. This could be because pathogen-related bacteria are more resistant to cleansing and quickly recolonize areas abandoned by their weaker siblings, similar to what happens to our gut after a course of antibiotics, according to scientists.
In a domestic environment, kitchens and bathrooms have a high potential to function as “microbial incubators” , due to the continuous inoculation of new microbial cells by the manipulation of food and the direct contact of the body with domestic surfaces. The successful colonization of these microbes depends on the suitability of environmental conditions, such as humidity, and the availability of nutrients.
Kitchen sponges not only act as a reservoir for microorganisms, but also as a spreader on household surfaces, which can lead to cross-contamination of hands and food, which is considered a leading cause of foodborne illness outbreaks.
The only solution to keep bacteria to a minimum in the kitchen, experts say, is to replace the kitchen sponge every week.
References:
Massimiliano Cardinale, Dominik Kaiser, Tillmann Lueders, Sylvia Schnell & Markus Egert. Microbiome analysis and confocal microscopy of used kitchen sponges reveal massive colonization by Acinetobacter, Moraxella and Chryseobacterium species. Scientific Reports 7, Article number: 5791 (2017). Doi: 10.1038 / s41598-017-06055-9
