Non-Bacterial Microbiota of Kitchen Sponges

The “built environment” of a modern household is colonized by many different bacteria, entering the household through humans, animals, plants, and foods. Kitchen sponges are particularly well known to harbor a high number and diversity of bacteria, including pathogens. Viruses, archaea, and eukaryotes in kitchen sponges, however, have not been examined in detail so far. In order to increase knowledge on the non-bacterial kitchen sponge microbiota and its potential hygienic rel-evance, we investigated five used kitchen sponges by means of metagenomic shot-gun sequenc-ing. Viral particles were slightly enriched by a filter step during DNA extraction from the sponges. Data analysis revealed that ~2% of the sequences could be assigned to non-bacterial taxa. Each sponge harbored an individual, dominant virus species, while the present archaea were predom-inantly affiliated with halophilic taxa. Among the eukaryotic taxa, besides more harmless algae, or amoebas, also DNA affiliated with a parasitic roundworm was found. The presented work offers new insights into the complex microbiota of used kitchen sponges and will help to better evaluate their hygienic relevance.