Severe acute respiratory syndrome coronavirus E protein transports calcium ions and activates the NLRP3 inflammasome

Severe acute respiratory syndrome coronavirus (SARS-CoV) envelope (E) protein is a viroporin involved in virulence. E protein ion channel (IC) activity is specifically correlated with enhanced pulmonary damage, edema accumulation and death. IL-1β driven proinflammation is associated with those pathological signatures, however its link to IC activity remains unknown. In this report, we demonstrate that SARS-CoV E protein forms protein–lipid channels in ERGIC/Golgi membranes that are permeable to calcium ions, a highly relevant feature never reported before. Calcium ions together with pH modulated E protein pore charge and selectivity. Interestingly, E protein IC activity boosted the activation of the NLRP3 inflammasome, leading to IL-1β overproduction. Calcium transport through the E protein IC was the main trigger of this process. These findings strikingly link SARS-CoV E protein IC induced ionic disturbances at the cell level to immunopathological consequences and disease worsening in the infected organism

Severe Acute Respiratory Syndrome Coronavirus Envelope Protein Ion Channel Activity Promotes Virus Fitness and Pathogenesis

Deletion of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) envelope (E) gene attenuates the virus. E gene encodes a small multifunctional protein that possesses ion channel (IC) activity, an important function in virus-host interaction. To test the contribution of E protein IC activity in virus pathogenesis, two recombinant mouse-adapted SARSCoVs, each containing one single amino acid mutation that suppressed ion conductivity, were engineered. After serial infections, mutant viruses, in general, incorporated compensatory mutations within E gene that rendered active ion channels. Furthermore, IC activity conferred better fitness in competition assays, suggesting that ion conductivity represents an advantage for the virus. Interestingly, mice infected with viruses displaying E protein IC activity, either with the wild-type E protein sequence or with the revertants that restored ion transport, rapidly lost weight and died. In contrast, mice infected with mutants lacking IC activity, which did not incorporate mutations within E gene during the experiment, recovered from disease and most survived. Knocking down E protein IC activity did not significantly affect virus growth in infected mice but decreased edema accumulation, the major determinant of acute respiratory distress syndrome (ARDS) leading to death. Reduced edema correlated with lung epithelia integrity and proper localization of Na+ /K+ ATPase, which participates in edema resolution. Levels of inflammasome-activated IL-1b were reduced in the lung airways of the animals infected with viruses lacking E protein IC activity, indicating that E protein IC function is required for inflammasome activation. Reduction of IL-1b was accompanied by diminished amounts of TNF and IL-6 in the absence of E protein ion conductivity. All these key cytokines promote the progression of lung damage and ARDS pathology. In conclusion, E protein IC activity represents a new determinant for SARS-CoV virulence

Patients receiving a high burden of antibiotics in the community in Spain: a cross-sectional study

Some patients in the community receive a high burden of antibiotics. We aimed at describing the characteristics of these patients, antibiotics used, and conditions for which they received antibiotics. We carried out a cross-sectional study. Setting: Thirty Health Primary Care Areas from 12 regions in Spain, covering 5, 960, 191 inhabitants. Patients having at least 30 packages of antibacterials for systemic use dispensed in 2017 were considered. Main outcome measures: Prevalence of antibiotic use, conditions for which antibiotics were prescribed, clinical characteristics of patients, comorbidities, concomitant treatments, and microbiological isolates. Patient''s average age was 70 years; 52% were men; 60% smokers/ex-smokers; 54% obese. Overall, 93% of patients had, at least, one chronic condition, and four comorbidities on average. Most common comorbidities were cardiovascular and/or hypertension (67%), respiratory diseases (62%), neurological/mental conditions (32%), diabetes (23%), and urological diseases (21%); 29% were immunosuppressed, 10% were dead at the time of data collection. Patients received three antibiotic treatments per year, mainly fluoroquinolones (28%), macrolides (21%), penicillins (19%), or cephalosporins (12%). Most frequently treated conditions were lower respiratory tract (infections or prophylaxis) (48%), urinary (27%), and skin/soft tissue infections (11%). Thirty-five percent have been guided by a microbiological diagnosis, being Pseudomonas aeruginosa (30%) and Escherichia coli (16%) the most frequent isolates. In conclusion, high antibiotic consumers in the community were basically elder, with multimorbidity and polymedication. They frequently received broad-spectrum antibiotics for long periods of time. The approach to infections in high consumers should be differentiated from healthy patients receiving antibiotics occasionally

Predictors of complications and mortality following left colectomy with primary stapled anastomosis for cancer: results of a multicentric study with 1111 patients

Aim: Reports detailing the morbidity–mortality after left colectomy are sparse and do not allow definitive conclusions to be drawn. We aimed to identify risk factors for anastomotic leakage, perioperative mortality and complications following left colectomy for colonic malignancies. Method: We undertook a STROBE-compliant analysis of left colectomies included in a national prospective online database. Forty-two variables were analysed as potential independent risk factors for anastomotic leakage, postoperative morbidity and mortality. Variables were selected using the ‘least absolute shrinkage and selection operator’ (LASSO) method. Results: We analysed 1111 patients. Eight per cent of patients had a leakage and in 80% of them reoperation or surgical drainage was needed. A quarter of patients (24.9%) experienced at least one minor complication. Perioperative mortality was 2%, leakage being responsible for 47.6% of deaths. Obesity (OR 2.8, 95% CI 1.00–7.05, P = 0.04) and total parenteral nutrition (TPN) (OR 3.7, 95% CI 1.58–8.51, P = 0.002) were associated with increased risk of leakage, whereas female patients had a lower risk (OR 0.36, 95% CI 0.18–0.67, P = 0.002). Corticosteroids (P = 0.03) and oral anticoagulants (P = 0.01) doubled the risk of complications, which was lower with hyperlipidaemia (OR 0.3, P = 0.02). Patients on TPN had more complications (OR 4.02, 95% CI 2.03–8.07, P = 0.04) and higher mortality (OR 8.7, 95% CI 1.8–40.9, P = 0.006). Liver disease and advanced age impaired survival, corticosteroids being the strongest predictor of mortality (OR 21.5, P = 0.001). Conclusion: Requirement for TPN was associated with more leaks, complications and mortality. Leakage was presumably responsible for almost half of deaths. Hyperlipidaemia and female gender were associated with lower rates of complications. These findings warrant a better understanding of metabolic status on perioperative outcome after left colectomy