Antibiotics and antibiotic resistance change bacterial community compositions in marine sediments.

Emerging contaminants, including antibiotics, antibiotic-resistant bacteria (ARB), and extracellular antibiotic resistance genes (eARGs), have been detected in large numbers in the aquatic environment. The effects of emerging contaminants on bacterial communities in marine sediments are not well studied. In this study, the effects of emerging contaminants (antibiotics, ARB, and eARGs) on the variations of bacterial populations in marine sediments of the Bohai Sea, Yellow Sea, East China Sea, and South China Sea were investigated. The results showed that the abundance of the host bacterial phylum Probacteria in the marine sediments of the Bohai Sea was the lowest among the four seas after exposure to different antibiotics, ARB, and eARGs. The inputs of exogenous antibiotics and resistance genes significantly affected the community function, resulting in significant differences in community abundance at the genus level. The abundance of Halomonas, Sulfitobacter, and Alcanivorax in the four sea areas displayed noteworthy differences in response to the addition of exogenous antibiotics and eARGs. These findings contribute to a more comprehensive understanding of the intricate interplay between emerging contaminants and the dynamics of bacterial communities in natural ecosystems.