Diversity and functional genomic insights into antimicrobial resistance and aromatic hydrocarbon degradation genes in the Red Sea coast microbial community.

INTRODUCTION

The Red Sea is a unique oligotrophic marine ecosystem characterized by high salinity, elevated temperatures, and increasing anthropogenic pressures along its coastal regions. However, coastal sediment-associated microbial communities and their functional potential, particularly regarding antimicrobial resistance and aromatic compound degradation, remain insufficiently explored.

METHODS

This study investigated bacterial diversity in coastal sediments from six sites along the eastern Red Sea using 16S rRNA gene amplicon sequencing and gained functional insights through genome sequencing of 21 cultured bacterial isolates.

RESULTS

Amplicon sequencing revealed diverse bacterial communities dominated by Proteobacteria, followed by Bacteroidetes and Planctomycetes. Alpha diversity indices showed no significant variation among sites, whereas beta diversity analysis demonstrated distinct community clustering influenced by environmental parameters, including temperature, salinity, and pH. Genomic analysis of 21 isolates identified multiple antimicrobial resistance genes (ARGs), conferring resistance to clinically relevant antibiotics such as beta-lactams, fluoroquinolones, and tetracyclines, alongside metal resistance determinants. Putative carbapenem resistance genes were detected in Vibrio and Idiomarina isolates. Genomic annotation predicted substantial variability in aromatic hydrocarbon degradation capacity among isolates. Genera including Marinobacter, Ruegeria, and Halomonas exhibited extensive gene interaction networks, indicating enhanced metabolic adaptability and bioremediation potential, whereas other taxa displayed limited functional connectivity, suggesting niche specialization.

CONCLUSION

Overall, this study identifies that Red Sea coastal sediments harbor taxonomically distinct bacterial communities that carry a reservoir of ARGs and possess pollutant-degradation capabilities, providing insights for environmental health monitoring and biotechnological applications in pollution remediation.