Clinical MRSA isolates from skin and soft tissue infections show increased in vitro production of phenol soluble modulins - 14/12/17
Summary |
Background |
Phenol-soluble modulins (PSMs) are amphipathic, pro-inflammatory proteins secreted by most Staphylococcus aureus isolates. This study tested the hypothesis that in vitro PSM production levels are associated with specific clinical phenotypes.
Methods |
177 methicillin-resistant S. aureus (MRSA) isolates from infective endocarditis (IE), skin and soft tissue infection (SSTI), and hospital-acquired/ventilator-associated pneumonia (HAP) were matched by geographic origin, then genotyped using spa-typing. In vitro PSM production was measured by high performance liquid chromatography/mass spectrometry. Statistical analysis was performed using Chi-squared or Kruskal–Wallis tests as appropriate.
Results |
Spa type 1 was significantly more common in SSTI isolates (62.7% SSTI; 1.7% IE; 16.9% HAP; p < 0.0001) while HAP and IE isolates were more commonly spa type 2 (0% SSTI; 37.3% IE; 40.7% HAP; p < 0.0001). USA300 isolates produced the highest levels of PSMs in vitro. SSTI isolates produced significantly higher quantities of PSMα1-4, PSMβ1, and δ-toxin than other isolates (p < 0.001). These findings persisted when USA300 isolates were excluded from analysis.
Conclusions |
Increased in vitro production of PSMs is associated with an SSTI clinical source. This significant association persisted after exclusion of USA300 genotype isolates from analysis, suggesting that PSMs play a particularly important role in the pathogenesis of SSTI as compared to other infection types.
Le texte complet de cet article est disponible en PDF.Highlights |
• | Clinical MRSA isolates from three infection types were grown in vitro. |
• | Supernatant was collected and quantitatively analyzed for 8 types of PSMs. |
• | Skin/soft tissue infection isolates had higher production of most PSM subtypes. |
• | This finding persisted after removing USA300 strains from the analysis. |
• | PSMs may play an enhanced role in skin/soft tissue infection pathogenesis. |
Keywords : Phenol soluble modulin, MRSA, Skin and soft tissue infection, Pneumonia, Endocarditis
Plan
Vol 71 - N° 4
P. 447-457 - octobre 2015 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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