The risk in stagnant drinking water: Combined stress of trace perfluorooctanoic acid (PFOA) and metal pollutants induces water quality deterioration and biofilm outbreaks

According to the metagenomic analysis, bacteria resist the stress of PFOA and metal pollutants by enhancing their cell envelope defense mechanisms, increasing carbon source metabolism, enhancing detoxification mechanisms, and increasing protein synthesis. For the distribution of bacterial communities, Pseudomonadota occupies the predominant position. The selection of trace PFOA and metal pollutants leads to a significant increase in the proportion of Actinomycetota. The stress from trace PFOA and metal pollutants leads to a certain degree of increase in ARGs and pathogenic genes. Additionally, species Pseudomonas aeruginosa, Salmonella enterica, Escherichia coli, Staphylococcus aureus were found in stagnant drinking water biofilms and are believed to pose an pose a risk of human infection. Fortunately, co-occurrence analysis suggests that the invasion of both does not contribute to the transmission of ARGs to pathogens.