Marine Bacteria as a Source of Antibiotics Against Staphylococcus aureus: Natural Compounds, Mechanisms of Action, and Discovery Strategies

<i>Staphylococcus aureus</i> is a major opportunistic pathogen responsible for a wide spectrum of human infections, including severe and difficult-to-treat cases. The emergence of multidrug-resistant strains limits the efficacy of conventional antibiotic therapies and poses a significant global public health challenge. In this context, the search for novel antibiotics has intensified, with increasing interest in marine resources, an ecosystem still largely underexplored. Marine bacteria produce a vast array of secondary metabolites with unique structures and potentially novel modes of antibacterial action. Several compounds isolated from marine bacterial strains have demonstrated promising activity against multidrug-resistant <i>S. aureus</i>, including antivirulence effects such as biofilm formation and <i>Quorum-Sensing</i> inhibition. This review explores the potential of marine bacteria as a source of new antibiotics against <i>S. aureus</i>, discusses both classical and advanced strategies for the discovery of bioactive molecules, and highlights the scientific and technological challenges involved in translating these findings into clinical applications.