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Klages, L. J.

Publications and source records attributed to Klages, L. J..

2 recordsLinked to original sources

Tyrosine availability shapes Staphylococcus aureus nasal colonization and interactions with commensal communities

Only certain individuals are nasally colonized by Staphylococcus aureus, making them more susceptible to developing endogenous infections. The role of the resident microbiota in modulating S. aureus nasal colonization remains largely unclear. Using a newly assembled nasal strain collection, we demonstrate that nasal commensals can either promote or inhibit S. aureus proliferation through strain- and community-specific effects in vitro and within gnotobiotic animals. We identified nutrient-dependent interactions as a key driver of these dynamics and found that S. aureus strains auxotrophic to tyrosine rely on amino acid-providing nasal communities to thrive in the nutrient-limited environment of the nose. Large-scale screenings revealed tyrosine dependency to affect 8% of nasal S. aureus strains and to impair S. aureus colonization. Our findings uncover a crucial factor in S. aureus physiology and its interactions as a commensal nasal species, paving the way for new decolonization strategies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/651429v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@17b6289org.highwire.dtl.DTLVardef@182249forg.highwire.dtl.DTLVardef@1324dc1org.highwire.dtl.DTLVardef@18ec3bf_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

Multiple transcription factors mediate acclimation of Chlamydomonas to light stress

Light as a substrate for photosynthesis may be a boon or a bane. To thrive, photosynthetic organisms must constantly respond to changing light and CO2 conditions by balancing energy harvest and consumption in a highly dynamic way. Two major safeguard measures of photoacclimation, that is photoprotection and carbon concentrating mechanism, underlie tight transcriptional control, leading to expression changes under high light and limited CO2 with different dynamics for both systems. Here, by using a consensus gene regulatory network inferred by employing a compendium of 1,869 RNA-seq datasets, we identified and validated in vivo eight candidate transcription factors (TFs) that contribute to photoacclimation in Chlamydomonas reinhardtii. Target gene analyses indicate that the TFs act individually in associated pathways but also influence each other in expression, and function as network parts with partial redundancy with respect to photoprotection. The analyses unveil that stress responses in Chlamydomonas are mediated by a complex, interconnected network of TFs rather than a hierarchical system where multiple regulators can influence each other and target gene expression and thereby mitigate the effects of loss.

plant biology↗