Metagenomic data from 12 aquaria for determination of the minimal selective concentration of tetracycline in complex communities

Selection pressure of antibiotics released into the environment could enrich for antibiotic resistance genes and antibiotic resistant bacteria, thus, increasing the risk for their transmission to humans and animals. Tetracyclines comprise an antibiotic class of importance to both human and animal health, and residues of tetracycline are commonly detected in aquatic environments. To assess if environmental pollution of tetracycline promotes development of resistance, we determined minimal selective concentrations (MSCs) in biofilms of complex aquatic bacterial communities using both phenotypic and genotypic assays. Taxonomic analyses of the biofilm communities suggested that composition was altered with increasing tetracycline concentrations. Metagenomic analysis revealed a concurrent increase of several tet genes and a range of other genes providing resistance to other classes of antibiotics, indicating co-selection potential. The methodology used here to assess MSCs could be applied in risk assessment of other antibiotics as well.