The dangerous transporters: A study of microplastic-associated bacteria passing through municipal wastewater treatment

Microplastics (MPs) provide a stable and protective habitat for diverse wastewater bacteria, including pathogenic and antibiotic-resistant species. Therefore, MPs may potentially transport these bacteria through wastewater treatment steps to the environment and far distances. This study investigated bacterial communities of MP - associated bacteria from different stages of municipal wastewater treatment processes to evaluate the poten- tial negative effect of these biofilms on the environment. The results showed a high diversity of bacteria that were strongly attached to MPs. After all treatment steps, the core bacterial groups remained attached to MPs and escaped from the wastewater treatment plant with effluent water. Several pathogenic bacteria were identified in MP samples from all treatment steps, and most of them were found in effluent water. These data provide new insights into the possible impacts of wastewater-derived MPs on the environment. MP-associated biofilms were proved to be important sources of pathogens and antibiotic-resistant genes in natural waters.

Automated summary

Microplastics can provide a stable habitat for diverse bacteria, including pathogens and antibiotic-resistant species, and facilitate their transport through wastewater treatment processes to the environment. This study found a high diversity of bacteria attached to microplastics at different stages of treatment, and these bacteria, including pathogenic strains, were able to escape into the effluent water of the treatment plant.