Nox2 is responsible for artery dysfunction via production of reactive oxidant species. RNA viruses may activate Nox2, but it is unknown if this occurs in coronavirus 2019(Covid-19). Nox2 activation by soluble Nox2-derived peptide(sNox2-dp) was measured in patients hospitalized for Covid-19 (n = 182) and controls (n = 91). sNox2-dp values were higher in Covid-19 patients versus controls and in severe versus non severe Covid-19. Patients with thrombotic events(n = 35,19%) had higher sNox2-dp than thrombotic event-free ones. A logistic regression analysis showed that sNox2 and coronary heart disease predicted thrombotic events. Oxidative stress by Nox2 activation is associated severe disease and thrombotic events in Covid-19 patients.

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INTRODUCTION: Patients with community-acquired pneumonia display enhanced levels of lipopolysaccharides (LPS) compared with controls, suggesting that low-grade endotoxemia may be implicated in vascular disturbances. It is unknown whether this occurs in patients with coronavirus 2019 (COVID-19) and its impact on thrombotic complications. METHODS: We measured serum levels of zonulin, a marker of gut permeability, LPS, and D-dimer in 81 patients with COVID-19 and 81 healthy subjects; the occurrence of thrombotic events in COVID-19 during the intrahospital stay was registered. RESULTS: Serum LPS and zonulin were higher in patients with COVID-19 than in control subjects and, in COVID-19, significantly correlated ( R = 0.513; P < 0.001). Among the 81 patients with COVID-19, 11 (14%) experienced thrombotic events in the arterial (n = 5) and venous circulation (n = 6) during a median follow-up of 18 days (interquartile range 11–27 days). A logistic regression analysis showed that LPS ( P = 0.024) and D-dimer ( P = 0.041) independently predicted thrombotic events. DISCUSSION: The study reports that low-grade endotoxemia is detectable in patients with COVID-19 and is associated with thrombotic events. The coexistence of low-grade endotoxemia with enhanced levels of zonulin may suggest enhanced gut permeability as an underlying mechanism.

Microbial translocation (MT) and intestinal damage (ID) are poorly explored in COVID-19. Aims were to assess whether alteration of gut permeability and cell integrity characterize COVID-19 patients, whether it is more pronounced in severe infections and whether it influences the development of subsequent bloodstream infection (BSI). Furthermore, we looked at the potential predictive role of TM and ID markers on Intensive Care Unit (ICU) admission and in-hospital mortality. Over March–July 2020, 45 COVID-19 patients were enrolled. Markers of MT [LPB (Lipopolysacharide Binding Protein) and EndoCab IgM] and ID [I-FABP (Intestinal Fatty Acid Binding Protein)] were evaluated at COVID-19 diagnosis and after 7 days. As a control group, age- and gender-matched healthy donors (HDs) enrolled during the same study period were included. Median age was 66 (56-71) years. Twenty-one (46.6%) were admitted to ICU and mortality was 22% (10/45). Compared to HD, a high degree of MT and ID was observed. ICU patients had higher levels of MT, but not of ID, than non-ICU ones. Likewise, patients with BSI had lower EndoCab IgM than non-BSI. Interestingly, patients with high degree of MT and low ID were likely to be admitted to ICU (AUC 0.822). Patients with COVID-19 exhibited high level of MT, especially subjects admitted to ICU. COVID-19 is associated with gut permeability.

Implant-associated infections are characterized by microbial biofilm formation on implant surface, which renders the microbiological diagnosis challenging and requires, in the majority of cases, a complete device removal along with a prolonged antimicrobial therapy. Traditional cultures have shown unsatisfactory sensitivity and a significant advance in the field has been represented by both the application of the sonication technique for the detachment of live bacteria from biofilm and the implementation of metabolic and molecular assays. However, despite the recent progresses in the microbiological diagnosis have considerably reduced the rate of culture-negative infections, still their reported incidence is not negligible. Overall, several culture- and non-culture based methods have been developed for diagnosis optimization, which mostly relies on pre-operative and intra-operative (i.e., removed implants and surrounding tissues) samples. This review outlines the principal culture- and non-culture based methods for the diagnosis of the causative agents of implant-associated infections and gives an overview on their application in the clinical practice. Furthermore, advantages and disadvantages of each method are described.