Bacterial biofilms colonizing plastics and microplastics in estuarine waters, with an emphasis on Vibrio spp. and their antibacterial resistance

Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural substrates and provide a novel habitat for colonization by bacterial communities. The spectrum of relationships between plastics and bacteria, however, is little understood. The first objective of this study was to examine plastics and microplastics as substrates for communities of Bacteria in estuarine surface waters. We used next-generation sequencing (NGS) of the 16S rRNA gene to characterize communities from microplastics collected in the field, and over the course of two colonization experiments, from biofilms that developed on polymers (low-density polyethylene, high-density polyethylene, polypropylene, polycarbonate, polystyrene) and glass. Field sampling and experiments were conducted in two estuarine tributaries of the lower Chesapeake Bay, the Elizabeth River and the Lafayette River, respectively. As a second objective, we concomitantly analyzed microplastics and biofilms on polymers to ascertain the presence and abundance of Vibrio spp. bacteria, then isolated three species known to be human pathogens, V. cholerae, V. parahaemolyticus, and V. vulnificus, and determined their antibiotic profiles. In both components of this study, we compared our results with analyses conducted on paired samples of estuarine water.