Three Fatal Cases of Rapidly Progressive Infective Endocarditis Caused by Staphylococcus Aureus One Case With Huge Vegetation

Staphylococcus aureus Serine protease-like protein A (SplA) induces IL-8 by keratinocytes and synergizes with IL-17A

BACKGROUND

Serine protease-like (Spl) proteins produced by Staphylococcus (S.) aureus have been associated with allergic inflammation. However, effects of Spls on the epidermal immune response have not been investigated.

OBJECTIVES

To assess the epidermal immune response to SplA, SplD and SplE dependent on differentiation of keratinocytes and a Th2 or Th17 cytokine milieu.

METHODS

Human keratinocytes of healthy controls and a STAT3-hyper-IgE syndrome (STAT3-HIES) patient were cultured in different calcium concentrations in the presence of Spls and Th2 or Th17 cytokines. Keratinocyte-specific IL-8 production and concomitant migration of neutrophils were assessed.

RESULTS

SplE and more significantly SplA, induced IL-8 in keratinocytes. Suprabasal-like keratinocytes showed a higher Spl-mediated IL-8 production and neutrophil migration compared to basal-like keratinocytes. Th17 cytokines amplified Spl-mediated IL-8 production, which correlated with neutrophil recruitment. Neutrophil recruitment by keratinocytes of the STAT3-HIES patient was similar to healthy control cells.

CONCLUSION

S. aureus-specific Spl proteases synergized with IL-17A on human keratinocytes with respect to IL-8 release and neutrophil migration, highlighting the importance of keratinocytes and Th17 immunity in barrier function.

More than Garden Variety: Massive Vegetations from Infective Endocarditis

Infective endocarditis classically involves non-sterile vegetations on valvular surfaces in the heart. Feared complications include embolization and acute heart failure. Surgical intervention achieves source control and alleviates valvular regurgitation in complicated cases. Vegetations >1 cm are often intervened upon, making massive vegetations uncommon in modern practice. We report the case of a 39-year-old female with history of intravenous drug abuse who presented with a serpiginous vegetation on the native tricuspid valve and methicillin-resistant Staphylococcus aureus bacteremia. The vegetation grew to 5.6 cm by hospital day two, and she successfully underwent a tricuspid valvectomy. Six weeks of intravenous vancomycin therapy were completed without adverse events. To better characterize other dramatic presentations of infective endocarditis, we performed a systematic literature review and summarized all case reports involving ≥4 cm vegetations.

Mild renal dysfunction on admission is an important prognostic predictor in patients with infective endocarditis: a retrospective single-center study

OBJECTIVE

Infective endocarditis (IE) continues to be associated with high mortality. The aim of the present study was to identify prognostic predictors for short-term mortality in patients with IE.

METHODS

We conducted a retrospective study of 119 consecutive patients with IE (mean age 58±17). Prognostic predictors for mortality at the early phase of admission were determined using a multivariate regression analysis, and a receiver operating characteristic (ROC) analysis was carried out to evaluate the predictive ability.

RESULTS

Eleven of 119 patients died during hospital admission. In this non-survivor group, the clinical parameters at the time of admission, including serum creatinine (Cr), the estimated glomerular filtration rate (eGFR), the red blood cell count, the white blood cell count, the serum CRP level and heart rate, differed significantly from those observed in the survivors (all; p<0.05). According to a logistic regression analysis, an increase in log-serum Cr per one standard deviation (odds ratio=2.18, 95%CI=1.08-4.41) and a decrease in log-eGFR per one standard deviation (odds ratio=0.51, 95%CI=0.26-0.98) were significantly associated with in-hospital death. The area under the ROC curve for serum Cr to predict the outcome was 0.80, the sensitivity was 64% and the specificity was 85% at a cut-off value of 1.16 mg/dL. For eGFR, the area under the ROC curve was 0.77, the sensitivity was 64% and the specificity was 86% at a cut-off value of 47.5 mL/min./1.73 m(2).

CONCLUSION

Mild renal dysfunction at the time of admission is an important predictor of early phase mortality in patients with IE.

Beneficial effects of probiotics in upper respiratory tract infections and their mechanical actions to antagonize pathogens

Probiotics are live micro‐organisms with beneficial effects on human health, which have the ability to counteract infections at different locations of the body. Clinical trials have shown that probiotics can be used as preventive and therapeutic agents in upper respiratory tract infections (URTIs) and otitis. Their mechanical properties allow them to aggregate and to compete with pathogens for nutrients, space and attachment to host cells. Consequently, they can directly antagonize pathogens and thus exert beneficial effects without directly affecting the metabolism of the host. An overview of the probiotics with such traits, tested up to date in clinical trials for the prevention or treatment of URTIs and otitis, is presented in this review. Their mechanical properties in the respiratory tract as well as at other locations are also cited. Species with interesting in vitro properties towards pharyngeal cells or against common respiratory pathogens have also been included. The potential safety risks of the cited species are then discussed. This review could be of help in the screening of probiotic strains with specific mechanical properties susceptible to have positive effects in clinical trials against URTIs.