Staphylococcus aureus Regulatory RNAs as Potential Biomarkers for Bloodstream Infections
Résumé
Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the transition from colonization to disease caused by this organism would be useful. Several S. aureus small RNAs (sRNAs) regulate virulence. We investigated presence and expression of 8 sRNAs in 83 S. aureus strains from 42 patients with sepsis or septic shock and 41 asymptomatic colonized carriers. Small pathogenicity island sRNAs sprB and sprC were clade specific. Six sRNAs had variable expression not correlated with clinical status. Expression of RNAIII was lower in strains from septic shock patients than in strains from colonized patients. When RNAIII was associated with expression of sprD, colonizing strains could be discriminated from strains in patients with bloodstream infections, including patients with sepsis and septic shock. Isolates associated with colonization might have sRNAs with target expression different from those of disease isolates. Monitoring expression of RNAIII and sprD could help determine severity of bloodstream infections.
Mots clés
nasal carrier
nasal colonization
second immunoglobulin-binding protein
sepsis
septic shock
small RNAs
multilocus sequence typing
immune evasion protein
bloodstream infections
biomarkers
bacteria
S. aureus protein A typing
Staphylococcus aureus
RNAIII
transfer–messenger RNA
staphylococci
small pathogenicity island RNAs
spa typing
spr RNAs