EVALUATION OF THE OCCURRENCE OF RESISTANCE GENES IN THE PLASTISPHERE OF THE SAO FRANCISCO CANAL - NITEROI, RJ

Plastic waste represents one of the most significant pollutants today, posing serious environmental concerns worldwide. One of the major issues related to plastic debris in the environment is the formation of microbial biofilms on its surfaces, which offer protection to various microorganisms, including pathogenic and antimicrobial-resistant bacteria. Although these bacteria are naturally found in water and sediments, plastic surfaces are considered hotspots for such microorganisms due to their highly favorable conditions for bacterial proliferation and horizontal gene transfer, thus harboring a high microbial diversity. The presence of antimicrobial resistance genes (ARGs) is among the most critical problems associated with coastal pollution, as multidrug-resistant bacteria can pose severe risks to human health, particularly for immunocompromised individuals. This study aims to assess microbial communities and the presence of ARGs in surface water, sediment, and plastic debris collected from the beach and the Sao Francisco Canal in Niteroi, Rio de Janeiro, Brazil. Microbial communities (bacteriome) were characterized using amplicon-based metagenomics through large-scale sequencing, while ARGs were detected via high-throughput PCR analysis. The sampling points across the canal revealed high microbial diversity. Notably, water, sediment, and plastic samples exhibited distinct microbial profiles, despite being collected from the same locations. Among the eleven ARGs investigated, all were detected in surface water and some sediment samples. These included one integron gene and ten genes associated with resistance to different classes of antimicrobials. These findings require further analysis and discussion to better understand the occurrence and ecological role of these microorganisms, as well as the environmental impact of ARGs in such ecosystems. Ultimately, this knowledge could inform mitigation strategies and guide public policies aimed at preventing outbreaks and potential epidemics.