Feast or famine: Nutrient sharing affects S. aureus growth in the nasal ecosystem
Simon Heilbronner
LMU Munich, Munich, Allemagne
The human nasal microbiome can serve as a reservoir for the opportunistic pathogen Staphylococcus aureus, increasing the risk of endogenous infections. Interactions with commensal bacteria are proposed to influence S. aureus carriage but the underlying mechanisms remain poorly understood.
Here, we show that nutrient availability is a key determinant of S. aureus fitness in the nasal environment. We identify biotin as a limiting resource that drives both competition and co-dependency among nasal microbes. Biotin depletion impairs S. aureus growth and membrane integrity, and both prototrophic and auxotrophic nasal species rely on high-affinity uptake systems to compete in this niche. Furthermore, we demonstrate that strain-specific metabolic adaptations shape S. aureus colonization. Using a nasal strain collection, in vitro assays, and gnotobiotic animal models, we show that tyrosine-auxotrophic S. aureus strains depend on amino acid–producing communities to persist under nutrient-limited conditions.
Together, our findings highlight nutrient sharing and metabolic specialization as central drivers of S. aureus colonization and underscore the importance of microbial community context in shaping pathogen persistence in the human nose.