This new study looks at the microbial species which can be found in used kitchen sponges. Using RNA sequencing, researchers were able to demonstrate that kitchen sponges harbour a higher bacterial diversity than previously thought, and that in contrast to previous studies close relatives of some potentially pathogenic species i.e. species which may cause disease in humans appeared as dominant taxa – although no cases in which an infection with these bacteria was explicitly reported from a domestic environment are recorded.
The results are not surprising since, within a domestic environment, kitchens and bathrooms have a high potential to function as “microbial incubators”, due to the continuous inoculation of new microbes cells, e.g. by food handling and direct body contact to the domestic surfaces; the colonization success of these microbes then depends on the suitability of the environmental conditions, such as humidity and nutrient availability.
The studies also suggested that current sponge sanitation methods are insufficient to effectively reduce the bacterial load in kitchen sponges and might even increase the predominance of risk-associated species The authrors therefore suggest a regular (and easily affordable) replacement of kitchen sponges, for example, on a weekly basis. The study can be found at