The small non-coding RNA RsaE influences extracellular matrix composition in Staphylococcus epidermidis biofilm...

Area of Science:

• Microbiology
• Molecular Biology
• Bacterial Pathogenesis

Background:

• Small regulatory RNAs (sRNAs) are key regulators of bacterial gene expression.
• RsaE is a known riboregulator in Staphylococcus aureus and Bacillus subtilis.
• Staphylococcus epidermidis forms biofilms crucial for infections.

Purpose of the Study:

• To investigate the role of RsaE in Staphylococcus epidermidis biofilm formation and matrix production.
• To elucidate the molecular mechanisms by which RsaE influences biofilm phenotypes, including extracellular DNA release and polysaccharide intercellular adhesin (PIA) production.

Main Methods:

• Differential RNA sequencing (dRNA-seq) to analyze global gene expression.
• Confocal laser scanning microscopy (CLSM) for biofilm visualization.
• Reporter gene fusions to study gene regulation.
• Northern blot analysis to characterize RsaE transcript forms.

Main Results:

• RsaE contributes to extracellular DNA release and promotes polysaccharide intercellular adhesin (PIA)-mediated biofilm matrix production in S. epidermidis.
• RsaE exists as full-length and processed forms, targeting different mRNAs (lrgA, icaR, sucCD).
• Overexpression of RsaE induces a PIA biofilm phenotype and extracellular DNA release.
• RsaE influences central carbon metabolism and PIA precursor synthesis.

Conclusions:

• RsaE acts as a critical riboregulator orchestrating biofilm matrix switching and extracellular DNA release in S. epidermidis.
• RsaE's dual transcript forms enable diverse regulatory functions, impacting bacterial lysis, biofilm matrix production, and metabolism.
• RsaE promotes phenotypic heterogeneity within S. epidermidis biofilms, potentially supporting community adaptation and division of labor.