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The Co‐HCW study is a prospective cohort study among hospital staff, including healthcare workers (HCWs) and administration staff, at the Jena University Hospital (JUH), Germany. The objectives of this study were to assess SARS‐CoV‐2 IgG seroprevalence, individual exposure risk factors and compliance of HCWs to wear personal protective equipment (PPE). After the first nosocomial COVID‐19 outbreak at JUH, mandatory masking was implemented on 20th March 2020. We evaluated point seroprevalence using two IgG detecting immunoassays and issued a questionnaire to assess COVID‐19 exposure, clinical symptoms and compliance to wear PPE. Antibody retesting was offered to participants with a divergent result of both immunoassays 5–10 weeks after the first test. Between 19th May and 19th June 2020, we analysed 660 participants [out of 3,228; 20.4%]. Among them, 212 participants (32.1%) had received a previous COVID‐19 test. Four of them (1.9%) reported a positive test result. After recruitment, 18 participants (2.7%) had SARS‐CoV‐2 antibodies in at least one immunoassay. Overall, 21 participants (3.2%) had any evidence of a past or current SARS‐CoV‐2 infection. Among them, 13 (61.9%) were not aware of direct COVID‐19 exposure and 9 (42.9%) did not report any clinical symptoms. COVID‐19 exposure at home (adjusted OR (aOR) with 95% CI: 47.82 (5.49, 416.62)) was associated with SARS‐CoV‐2 seroprevalence. We observed no evidence for an association between seroprevalence and exposure at work (aOR 0.48 (0.13, 1.70)) or with COVID‐19 risk area according to the working place (aOR for intermediate‐risk vs. high‐risk: 1.97 (0.42, 9.22), aOR for low‐risk versus high‐risk: 2.10 (0.40, 11.06); p = .655). Reported compliance of HCWs to wear PPE differed (p

The similarities and differences between trained immunity and other immune processes are the subject of intense interrogation. Therefore, a consensus on the definition of trained immunity in both in vitro and in vivo settings, as well as in experimental models and human subjects, is necessary for advancing this field of research. Here we aim to establish a common framework that describes the experimental standards for defining trained immunity.

Background Herpes simplex virus type 1 (HSV-1) is frequently detected in the BAL fluid of patients on mechanical ventilation. Research Question The aim of the study was to investigate whether antiviral therapy is associated with improved overall survival within 30 days. Study Design and Methods This was a retrospective cohort study in four ICUs between January 2011 and December 2017. All adult patients on mechanical ventilation with a respiratory tract infection with positive polymerase chain reaction testing for HSV-1 in the BAL were included. Patients already receiving antiviral agents on the day BAL was performed were excluded. We performed uni- and multivariable Cox and logistic regression modeling. Results Overall, 306 patients were included in the analysis. Among them, 177 patients (57.8%) received antiviral therapy (90.9% acyclovir, 6.2% ganciclovir, 2.9% both). The overall 30-day mortality rate was 42.4% (n = 75) in the antiviral treatment group and 50.4% (n = 65) in the control group. The adjusted hazard ratio (HR) for the primary outcome was 0.62 (95% CI, 0.44-0.87; P = .005), indicating better overall survival within 30 days for the antiviral-treated group than for the untreated group. This benefit was also present in the subgroup of patients without immunosuppression (n = 246; adjusted HR, 0.53; 95% CI, 0.36-0.78; P = .001). Overall, the median lengths of hospital stay (31 vs 24 days, P = .002) and ICU stay (24 vs 17 days, P Interpretation These data suggest that detection of HSV-1 in the BAL of patients on mechanical ventilation may be of clinical significance and that specific antiviral treatment may improve clinical outcomes. However, this needs to be proven in multicenter randomized controlled trials before implementation into the clinical routine.

Antibiotic resistance is a part of bacterial evolution and therefore unavoidable. Scarcity of novel treatment options requires prudent use of available antibiotics in order to decelerate the spread of resistance. This is the aim of antibiotic stewardship (ABS) programmes. The implementation of strategies that optimize antibiotic prescription and therapy necessitates the deployment of personnel as well as of structural resources. Necessary requirements for staff and strategies based on their evidence are described in the updated German S3 ABS Guideline. In the future, patients with infectious diseases will benefit from accelerated microbiological diagnostics as early adequate treatment not only reduces antibiotic consumption but also improves patient outcome. In addition, training of infectious disease specialists will substantially contribute to enhanced quality of care of patients with infectious disease.

Significance Sepsis remains a leading cause of death. New insights into its pathophysiology are likely to be key to the development of effective therapeutic strategies against sepsis. Given the role of GDF15 in metabolism regulation and in cachexia during late stages of cancer, features that also occur in sepsis, elucidation of the possible mechanistic role of GDF15 in sepsis is of great importance. We find that septic patients have very high levels of GDF15 in the peripheral blood, which correlate with clinical outcomes. Using Gdf15-deficient mice, we show that GDF15 plays a causal role in sepsis by delaying the local control of infection. These findings suggest GDF15 as a potential therapeutic target in sepsis secondary to a bacterial infection., Sepsis is a life-threatening organ dysfunction condition caused by a dysregulated host response to an infection. Here we report that the circulating levels of growth and differentiation factor-15 (GDF15) are strongly increased in septic shock patients and correlate with mortality. In mice, we find that peptidoglycan is a potent ligand that signals through the TLR2-Myd88 axis for the secretion of GDF15, and that Gdf15-deficient mice are protected against abdominal sepsis due to increased chemokine CXC ligand 5 (CXCL5)-mediated recruitment of neutrophils into the peritoneum, leading to better local bacterial control. Our results identify GDF15 as a potential target to improve sepsis treatment. Its inhibition should increase neutrophil recruitment to the site of infection and consequently lead to better pathogen control and clearance.

ZUSAMMENFASSUNGBlutstrominfektionen durch Staphylococcus aureus sind schwere Infektionserkrankungen, die mit dem Risiko von sekundären Absiedlungen, Rekurrenzen und hohen Sterblichkeitsraten assoziiert sind. Bei adäquater Diagnostik und Therapie kann das Outcome wesentlich verbessert werden. Alle Patienten mit Staphylococcus-aureus-Bakteriämie sollten infektiologisch betreut werden, um die Einhaltung der Therapiestandards zu gewährleisten. Medikamente der Wahl sind Cefazolin und Flucloxacillin bei MSSA und Daptomycin (cave: nicht bei pulmonalem Fokus) und Vancomycin bei MRSA-Infektionen. Die Therapie sollte für mindestens 14 Tage intravenös erfolgen. Inwiefern eine Oralisierung bei Patienten mit unkomplizierten Bakteriämien erfolgen kann, ist derzeit Gegenstand von Studien. Erste Daten lassen drauf schließen.

Zusammenfassung Hintergrund Staphylococcus aureus ist der zweithäufigste Erreger von Blutstrominfektionen. Das klinische Management einer S.-aureus-Blutstrominfektion (SAB) unterscheidet sich von dem bei Blutstrominfektionen durch andere Erreger. Gründe hierfür sind der komplikationsträchtige Verlauf, die hohe Krankenhaussterblichkeit (15 – 40%) und das häufigere Auftreten von Rezidiven. Methoden Es erfolgte eine selektive Literaturrecherche in PubMed. In die Analyse wurden die aktuellen Leitlinien- und Expertenempfehlungen einbezogen. Ergebnis Der Nachweis von S. aureus in der Blutkultur sollte grundsätzlich als klinisch relevant betrachtet werden. Mittel der Wahl zur Therapie bei einer Blutstrominfektion mit Methicillin-sensiblen S. aureus ist Flucloxacillin (8 – 12 g i. v./d). Bei einer Blutstrominfektion mit Methicillin-resistenten S. aureus (MRSA) werden Vancomycin oder Daptomycin (letzteres nicht bei pneumogenem Fokus) empfohlen. Die Abnahme von Folgeblutkulturen, eine intensive Fokussuche einschließlich transösophagealer Echokardiografie bei Patienten mit Risikoprofil und eine rasche Fokussanierung sind wichtige Maßnahmen. Die Therapiedauer beträgt bei unkomplizierter SAB mindestens 14 Tage, wobei die gesamte Therapie intravenös durchgeführt werden soll. Bei komplizierter SAB wird eine Gesamttherapiedauer von mindestens 4 – 6 Wochen empfohlen. Durch Adhärenz an dieses Maßnahmenbündel kann die Sterblichkeit um bis zu 50% reduziert werden. Schlussfolgerung Die SAB geht mit einer hohen Morbidität und Letalität einher. Das klinische Management ist komplex. Durch Einhaltung von diagnostischen und therapeutischen Maßnahmen kann die Prognose verbessert werden.

Hydrogen sulfide (H2S) has recently been recognized as a novel gaseous transmitter with several anti-inflammatory properties. The role of host- derived H2S in infections by Pseudomonas aeruginosa was investigated in clinical and mouse models. H2S concentrations and survival was assessed in septic patients with lung infection. Animal experiments using a model of severe systemic multidrug-resistant P. aeruginosa infection were performed using mice with a constitutive knock-out of cystathionine-γ lyase (Cse) gene (Cse-/-) and wild-type mice with a physiological expression (Cse+/+). Experiments were repeated in mice after a) treatment with cyclophosphamide; b) bone marrow transplantation (BMT) from a Cse+/+ donor; c) treatment with H2S synthesis inhibitor aminooxyacetic acid (ΑΟΑΑ) or propargylglycine (PAG) and d) H2S donor sodium thiosulfate (STS) or GYY3147. Bacterial loads and myeloperoxidase activity were measured in tissue samples. The expression of quorum sensing genes (QS) was determined in vivo and in vitro. Cytokine concentration was measured in serum and incubated splenocytes. Patients survivors at day 28 had significantly higher serum H2S compared to non-survivors. A cut- off point of 5.3 μΜ discriminated survivors with sensitivity 92.3%. Mortality after 28 days was 30.9% and 93.7% in patients with H2S higher and less than 5.3 μΜ (p = 7 x 10−6). In mice expression of Cse and application of STS afforded protection against infection with multidrug-resistant P. aeruginosa. Cyclophosphamide pretreatment eliminated the survival benefit of Cse+/+ mice, whereas BMT increased the survival of Cse-/- mice. Cse-/- mice had increased pathogen loads compared to Cse+/+ mice. Phagocytic activity of leukocytes from Cse-/- mice was reduced but was restored after H2S supplementation. An H2S dependent down- regulation of quorum sensing genes of P.aeruginosa could be demonstrated in vivo and in vitro. Endogenous H2S is a potential independent parameter correlating with the outcome of P. aeruginosa. H2S provides resistance to infection by MDR bacterial pathogens., Author summary Multidrug- resistant Pseudomonas (P.) aeruginosa is one of the most common causes of ventilator-associated pneumonia (VAP), which consist one of the most common causes of sepsis in hospitalized patients. The increasing antimicrobial resistance of P. aeruginosa necessitates the investigation of new treatment strategies. In this study we highlight host derived hydrogen sulfide (H2S), produced by cystathionine-γ-lyase (CSE), as a new protective mechanism against Pseudomonas aeruginosa infection. We have shown that serum H2S levels above 5.3μM can discriminate survivors of P.aeruginosa related sepsis with high sensitivity and is correlated with reduced mortality. We verified this finding in an animal model of CSE knockout mice. The protective role of endogenous H2S resides in the enhancement of neutrophil recruitment and the phagocytic activity of neutrophils, as well as by inhibiting the cell-to-cell communication system of P. aeruginosa (quorum sensing system), rendering it more vulnerable to phagocytosis.

Contains fulltext : 235065.pdf (Publisher’s version ) (Closed access) The zoonotic SARS-CoV-2 virus that causes COVID-19 continues to spread worldwide, with devastating consequences. While the medical community has gained insight into the epidemiology of COVID-19, important questions remain about the clinical complexities and underlying mechanisms of disease phenotypes. Severe COVID-19 most commonly involves respiratory manifestations, although other systems are also affected, and acute disease is often followed by protracted complications. Such complex manifestations suggest that SARS-CoV-2 dysregulates the host response, triggering wide-ranging immuno-inflammatory, thrombotic, and parenchymal derangements. We review the intricacies of COVID-19 pathophysiology, its various phenotypes, and the anti-SARS-CoV-2 host response at the humoral and cellular levels. Some similarities exist between COVID-19 and respiratory failure of other origins, but evidence for many distinctive mechanistic features indicates that COVID-19 constitutes a new disease entity, with emerging data suggesting involvement of an endotheliopathy-centred pathophysiology. Further research, combining basic and clinical studies, is needed to advance understanding of pathophysiological mechanisms and to characterise immuno-inflammatory derangements across the range of phenotypes to enable optimum care for patients with COVID-19.

Objectives Histone methyltransferase G9a, also known as Euchromatic Histone Lysine Methyltransferase 2 (EHMT2), mediates H3K9 methylation which is associated with transcriptional repression. It possesses immunomodulatory effects and is overexpressed in multiple types of cancer. In this study, we investigated the role of G9a in the induction of trained immunity, a de facto innate immune memory, and its effects in non‐muscle‐invasive bladder cancer (NMIBC) patients treated with intravesical Bacillus Calmette‐Guérin (BCG). Methods EHMT2 expression was assessed upon induction of trained immunity by RNA sequencing and Western blotting. G9a inhibitor BIX‐01294 was used to investigate the effect on trained immunity responses in vitro. Subsequent cytokine production was measured by ELISA, epigenetic modifications were measured by ChIP‐qPCR, Seahorse technology was used to measure metabolic changes, and a luminescence assay was used to measure ROS release. RNA sequencing was performed on BIX‐01294‐treated monocytes ex vivo. Results The expression of EHMT2 mRNA and protein decreased in monocytes during induction of trained immunity. G9a inhibition by BIX‐01294 induced trained immunity and amplified trained immunity responses evoked by various microbial ligands in vitro. This was accompanied by decreased H3K9me2 at the promoters of pro‐inflammatory genes. G9a inhibition was also associated with amplified ex vivo trained immunity responses in circulating monocytes of NMIBC patients. Additionally, altered RNA expression of inflammatory genes in monocytes of NMIBC patients was observed upon ex vivo G9a inhibition. Furthermore, intravesical BCG therapy decreased H3K9me2 at the promoter of pro‐inflammatory genes. Conclusion Inhibition of G9a is important in the induction of trained immunity, and G9a may represent a novel therapeutic target in NMIBC patients., In this study, we show that G9a inhibits induction of trained immunity in human monocytes. Pharmacological G9a inhibition enhances trained immunity responses, accompanied by decreased H3K9me2 marks at pro‐inflammatory genes. Additionally, ex vivo G9a inhibition was associated with amplified trained immunity responses in monocytes derived from non‐muscle‐invasive bladder cancer patients and altered RNA expression of inflammatory genes.

Most mammals express a functional GGTA1 gene encoding the N-acetyllactosaminide α-1,3-galactosyltransferase enzyme, which synthesizes Gal-α1-3Gal-β1-4GlcNAc (α-gal) and are thus tolerant to this self-expressed glycan. Old World primates including humans, however, carry loss-of-function mutations in GGTA1 and lack α-gal. Presumably, fixation of such mutations was propelled by natural selection, favoring the emergence of α-gal-specific immunity, conferring resistance to α-gal-expressing pathogens. Here, we show that loss of Ggta1 function in mice enhances resistance to bacterial sepsis, irrespectively of α-Gal-specific immunity. Rather, the absence of α-gal from IgG-associated glycans increases IgG effector function via a mechanism associated with enhanced IgG-Fc gamma receptor (FcγR) binding. The ensuing survival advantage against sepsis comes alongside a cost of accelerated reproductive senescence in Ggta1-deleted mice. Mathematical modeling of this trade-off suggests that high exposure to virulent pathogens exerts sufficient selective pressure to fix GGTA1 loss-of-function mutations, as likely occurred during the evolution of primates toward humans.

Trained immunity defines long-lasting adaptive responses of innate immunity, mediated by transcriptional and epigenetic modifications of myeloid cells. Here, we report that labile heme, an alarmin released extracellularily upon tissue damage and hemolysis, induces trained immunity in human and murine primary cells and in mice. Heme-trainning in monocytes is associated with epigenetic and transcriptional profiles that overlap to some extent with those seen in β-glucan-training, the prototype agonist of trained immunity. In sharp contrast to β-glucan training however, heme-training relied on activation of the Syk/JNK-pathway. Heme training in mice was associated with long-lasting expansion of myeloid-biased progenitor cells as well as with altered chromatin accessibility in hematopoietic stem and progenitor cells. Finally, heme-induced training was protective against bacterial sepsis in mice.In conclusion, we reveal that heme, a bona fide alarmin, induces innate immune memory regulating host response to infection.

Einleitung Staphylococcus-aureus-Bakteriamien sind schwere Infektionserkrankungen mit oftmals langwierigen klinischen Verlaufen und hoher Sterblichkeit. Retrospektive Studien zeigen, dass infektiologische Konsile die Adharenz an Therapiestandards erhohen und das Uberleben von Staphylococcus-aureus-Bakteriamie-Patienten verbessern konnen. Methoden In dieser retrospektiven, monozentrischen Beobachtungsstudie wurde der Einfluss von infektiologischen Konsilen auf das Uberleben von Patienten mit Staphylococcus-aureus-Bakteriamie am Universitatsklinikum Jena mittels logistischer Regressions- und Uberlebenszeitanalyse untersucht. Der primare Endpunkt der Studie war die Krankenhaussterblichkeit. Ergebnisse Insgesamt wurden Daten von 297 Patienten (≥ 18 Jahre) mit Staphylococcus-aureus-Bakteriamie im Zeitraum zwischen Dezember 2012 und August 2015 analysiert. Bei 159 dieser Patienten wurde ein infektiologisches Konsil durchgefuhrt. Die Durchfuhrung eines Konsils war mit einer geringeren Krankenhaussterblichkeit assoziiert (23 % ohne Konsil, 11 % mit Konsil; multiple Regressionsanalyse: Odds-Ratio = 0,27 [95 %-Konfidenzintervall: 0,12 – 0,64]; p = 0,003). Ferner gab es Unterschiede bei der Erfullung definierter Qualitatsindikatoren der Behandlung einer Staphylococcus-aureus-Bakteriamie. Dabei war die komplette Umsetzung aller im Konsil empfohlenen Masnahmen mit der niedrigsten Krankenhaussterblichkeit verbunden. Diskussion Die Mitbehandlung von Patienten mit Staphylococcus-aureus-Bakteriamie durch klinische Infektiologen war mit einer geringeren Krankenhaussterblichkeit assoziiert. Background Staphylococcus aureus bacteraemia is frequently associated with complications and a high mortality. Recent retrospective studies provide evidence that infectious disease specialist consultations improve the outcome of patients with Staphylococcus aureus bacteraemia by increasing adherence to treatment standards. Methods In this retrospective, single-centre observational study, we investigated the impact of infectious disease consultations on the outcome of patients with Staphylococcus aureus bacteraemia at the Jena University Hospital applying logistic regression and survival analyses. The primary endpoint was intra-hospital mortality. Results We analysed patients (≥ 18 years) with Staphylococcus aureus bacteraemia between December 2012 and August 2015 (n = 297), of whom 159 received infectious disease consultations. Specialist consultations were associated with lower intra-hospital mortality (23 % without consultations, 11 % with consultations; multiple regression analysis: odds ratio = 0.27 [95 % confidence interval: 0.12 – 0.64]; p = 0.003). Furthermore, the adherence to defined quality-of-care indicators differed. The complete implementation of all recommendations was associated with the lowest intra-hospital mortality rates. Conclusion Infectious disease consultations in patients with Staphylococcus aureus bacteraemia were associated with a lower intra-hospital mortality rate.

Several classes of antibiotics have long been known to have beneficial effects that cannot be explained strictly on the basis of their capacity to control the infectious agent. Here, we report that tetracycline antibiotics, which target the mitoribosome, protected against sepsis without affecting the pathogen load. Mechanistically, we found that mitochondrial inhibition of protein synthesis perturbed the electron transport chain (ETC) decreasing tissue damage in the lung and increasing fatty acid oxidation and glucocorticoid sensitivity in the liver. Using a liver-specific partial and acute deletion of Crif1, a critical mitoribosomal component for protein synthesis, we found that mice were protected against sepsis, an observation that was phenocopied by the transient inhibition of complex I of the ETC by phenformin. Together, we demonstrate that mitoribosome-targeting antibiotics are beneficial beyond their antibacterial activity and that mitochondrial protein synthesis inhibition leading to ETC perturbation is a mechanism for the induction of disease tolerance.

SummarySynergy of resistance and disease tolerance mechanisms is necessary for an effective immune response leading to survival and return to homeostasis when an organism is challenged by infection. Antibiotics are used for their resistance enhancement capabilities by decreasing pathogen load, but several classes have long been known to have beneficial effects that cannot be explained strictly on the basis of their capacity to control the infectious agent. Here we report that tetracycline antibiotics, a class of ribosome-targeting drugs, robustly protects against sepsis by inducing disease tolerance, independently from their direct antibiotic properties. Mechanistically, we find that mitochondrial inhibition of protein synthesis perturbs the electron transfer chain and leads to improved damage repair in the lung and fatty acid oxidation and glucocorticoid sensitivity in the liver. Using a partial and acute deletion ofCRIF1in the liver, a critical mitoribosomal component for protein synthesis, we find that mice are protected against bacterial sepsis, an observation which is phenocopied by the transient inhibition of complex I of ETC by phenformin. Together, we demonstrate that ribosome-targeting antibiotics are beneficial beyond their antibacterial activity and that mitochondrial protein synthesis inhibition leading to ETC perturbation is a novel mechanism for the induction of disease tolerance.

Here, we report the case of an HIV positive patient under a dual antiretroviral drug regimen with tenofovir disoproxil and darunavir/ritonavir with stable clinical, virological, and immunological response over 126 weeks. Dual antiretroviral therapy has the advantage of reduced toxicity and lower health care costs, treatment failure and fostering drug resistance are perceived risks. Optimal drug combinations and indication criteria for dual treatment remain controversial. Nevertheless, first clinical trials indicate non-inferiority for combinations of nucleoside reverse transcriptase inhibitors and protease inhibitors. This case presents the combination of tenofovir disoproxil in combination with a protease inhibitor as a new potential dual treatment regimen. We performed a systematic literature search and meta-analysis of trials comparing dual to triple ART. Literature review revealed nine studies in which dual therapy with a protease inhibitor and an NRTI was compared to triple therapy. We performed a meta-analysis of six trials that reported a 48-week follow-up. In treatment-naive patients as well when ART switch was assessed, there was no difference in the treatment success in patients with dual ART versus triple. We conclude that dual therapy with a protease inhibitor and NRTI is safe and effective. The use of tenofovir in dual treatment as described in our case needs to be assessed in future clinical trials.

Urosepsis is defined as a severe disease due to organ failure caused by a urinary tract infection. An empirical antibiotic therapy should be instigated within the first hour after diagnosis. Urine cultures and blood cultures should be performed before antibiotic treatment. Further diagnostics should be carried out at an early stage to enable an interventional focus control in the case of urinary tract obstruction or abscess formation, if necessary. Gram-negative pathogens are most frequently isolated. Extended spectrum beta-lactamase (ESBL) forming bacteria as a cause of urosepsis are increasing. Carbapenemase-forming Enterobacteriaceae, on the other hand, are still rare. The empirical treatment consists of a broad spectrum beta-lactam antibiotic. While piperacillin/tazobactam, carbapenems and the new cephalosporin/beta-lactamase inhibitor (BLI) combinations are given as monotherapy, cephalosporins should be combined with aminoglycosides (preferred) or fluoroquinolones. If a combination therapy is given, it should be de-escalated to a monotherapy after 48-72 h.

Rates of antibiotic resistance are increasing worldwide and impact on the treatment of patients with bacterial infections. A broad and uncritical application in inpatient and outpatient settings as well as in agriculture has been recognized as the main driving force. Antibiotic stewardship (ABS) programs aim at countering this worrisome development using various direct interventions such as infectious disease counseling. Blood stream infections caused by Staphylococcus (S.) aureus are severe infections associated with high mortality rates. ABS interventions such as de-eskalation of the antibiotic regimen or application of narrow-spectrum beta-lactam antibiotics can significantly reduce mortality rates. In this review, we discuss the importance of ABS programs and infectious disease counseling for the treatment of S. aureus blood stream infection.

Complex immune dysregulation is a hallmark of sepsis. The occurring phases of immunosuppression and hyperinflammation require rapid detection and close monitoring. Reliable tools to monitor patient’s immune status are yet missing. Currently, microRNAs are being discussed as promising new biomarkers in sepsis. However, no suitable internal control for normalization of miRNA expression by qPCR has been validated so far, thus hampering their potential benefit. We here present the first evaluation of endogenous controls for miRNA analysis in human sepsis. Novel candidate reference miRNAs were identified via miRNA microArray. TaqMan qPCR assays were performed to evaluate these microRNAs in T-cells and whole blood cells of sepsis patients and healthy controls in two independent cohorts. In T-cells, U48 and miR-320 proved suitable as endogenous controls, while in whole blood cells, U44 and miR-942 provided best stability values for normalization of miRNA quantification. Commonly used snRNA U6 exhibited worst stability in all sample groups. The identified internal controls have been prospectively validated in independent cohorts. The critical importance of housekeeping gene selection is emphasized by exemplary quantification of imuno-miR-150 in sepsis patients. Use of appropriate internal controls could facilitate research on miRNA-based biomarker-use and might even improve treatment strategies in the future.

Background Sepsis, the most severe form of infection, involves endothelial dysfunction which contributes to organ failure. To improve therapeutic prospects, elucidation of molecular mechanisms underlying endothelial vascular failure is of essence. Methods Polymicrobial contamination induced sepsis mouse model and primary endothelial cells incubated with sepsis serum were used to study SHP-2 in sepsis-induced endothelial inflammation. SHP-2 activity was assessed by dephosphorylation of pNPP, ROS production was measured by DCF oxidation and protein interactions were assessed by proximity ligation assay. Vascular inflammation was studied in the mouse cremaster model and in an in vitro flow assay. Findings We identified ROS-dependent inactivation of the tyrosine phosphatase SHP-2 to be decisive for endothelial activation in sepsis. Using in vivo and in vitro sepsis models, we observed a significant reduction of endothelial SHP-2 activity, accompanied by enhanced adhesion molecule expression. The impaired SHP-2 activity was restored by ROS inhibitors and an IL-1 receptor antagonist. SHP-2 activity inversely correlated with the adhesive phenotype of endothelial cells exposed to IL-1β as well as sepsis serum via p38 MAPK and NF-κB. In vivo, SHP-2 inhibition accelerated IL-1β-induced leukocyte adhesion, extravasation and vascular permeability. Mechanistically, SHP-2 directly interacts with the IL-1R1 adaptor protein MyD88 via its tyrosine 257, resulting in reduced binding of p85/PI3-K to MyD88. Interpretation Our data show that SHP-2 inactivation by ROS in sepsis releases a protective break, resulting in endothelial activation. Fund German Research Foundation, LMU Mentoring excellence and FoFoLe Programme, Verein zur Forderung von Wissenschaft und Forschung, German Ministry of Education and Research.

Objective The ferritin heavy/heart chain (FTH) gene encodes the ferroxidase component of the iron (Fe) sequestering ferritin complex, which plays a central role in the regulation of cellular Fe metabolism. Here we tested the hypothesis that ferritin regulates organismal Fe metabolism in a manner that impacts energy balance and thermal homeostasis. Methods We developed a mouse strain, referred herein as FthR26 fl/fl, expressing a tamoxifen-inducible Cre recombinase under the control of the Rosa26 (R26) promoter and carrying two LoxP (fl) sites: one at the 5′end of the Fth promoter and another the 3' end of the first Fth exon. Tamoxifen administration induces global deletion of Fth in adult FthR26Δ/Δ mice, testing whether FTH is required for maintenance of organismal homeostasis. Results Under standard nutritional Fe supply, Fth deletion in adult FthR26Δ/Δ mice led to a profound deregulation of organismal Fe metabolism, oxidative stress, inflammation, and multi-organ damage, culminating in death. Unexpectedly, Fth deletion was also associated with a profound atrophy of white and brown adipose tissue as well as with collapse of energy expenditure and thermogenesis. This was attributed mechanistically to mitochondrial dysfunction, as assessed in the liver and in adipose tissue. Conclusion The FTH component of ferritin acts as a master regulator of organismal Fe homeostasis, coupling nutritional Fe supply to organismal redox homeostasis, energy expenditure and thermoregulation., Highlights • Ferritin acts as a master regulator of organismal iron metabolism. • Regulation of Fe metabolism by Ferritin sustains organismal redox homeostasis. • Ferritin is essential to support organismal energy expenditure and thermogenesis. • Ferritin is essential to support mitochondrial function and integrity in parenchymal tissues.

Sepsis is a life-threatening clinical syndrome defined as a deregulated host response to infection associated with organ dysfunction. Mechanisms underlying the pathophysiology of septic liver dysfunction are incompletely understood. Among others, the iron containing tetrapyrrole heme inflicts hepatic damage when released into the circulation during systemic inflammation and sepsis. Accordingly, hemolysis and decreased concentrations of heme-scavenging proteins coincide with an unfavorable outcome of critically ill patients. As the liver is a key organ in heme metabolism and host response to infection, we investigated the impact of labile heme on sinusoidal microcirculation and hepatocellular integrity. We here provide experimental evidence that heme increases portal pressure via a mechanism that involves hepatic stellate cell-mediated sinusoidal constriction, a hallmark of microcirculatory failure under stress conditions. Moreover, heme exerts direct cytotoxicity in vitro and aggravates tissue damage in a model of polymicrobial sepsis. Heme binding by albumin, a low-affinity but high-capacity heme scavenger, attenuates heme-mediated vasoconstriction in vivo and prevents heme-mediated cytotoxicity in vitro. We demonstrate that fractions of serum albumin-bound labile heme are increased in septic patients. We propose that heme scavenging might be used therapeutically to maintain hepatic microcirculation and organ function in sepsis.

Model animal; COVID-19; Recerca preclínica Modelo animal; COVID-19; Investigación preclínica Animal model; COVID-19; Pre-clinical research Many milestones in medical history rest on animal modeling of human diseases. The SARS-CoV-2 pandemic has evoked a tremendous investigative effort primarily centered on clinical studies. However, several animal SARS-CoV-2/COVID-19 models have been developed and pre-clinical findings aimed at supporting clinical evidence rapidly emerge. In this review, we characterize the existing animal models exposing their relevance and limitations as well as outline their utility in COVID-19 drug and vaccine development. Concurrently, we summarize the status of clinical trial research and discuss the novel tactics utilized in the largest multi-center trials aiming to accelerate generation of reliable results that may subsequently shape COVID-19 clinical treatment practices. We also highlight areas of improvement for animal studies in order to elevate their translational utility. In pandemics, to optimize the use of strained resources in a short time-frame, optimizing and strengthening the synergy between the preclinical and clinical domains is pivotal.

Objectives Due to a substantial proportion of asymptomatic and mild courses, many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections remain unreported. Therefore, assessment of seroprevalence may detect the real burden of disease. We aimed to determine and characterize the rate of SARS-CoV-2 infections and the resulting seroprevalence in a defined population. The primary objective of the study was to assess SARS-CoV-2 antibody seroprevalence using six different IgG-detecting immunoassays. Secondary objectives of the study were: (a) to determine potential risk factors for symptomatic versus asymptomatic coronavirus disease 2019 courses, and (b) to investigate the rate of virus RNA-persistence. Methods CoNAN is a population-based cohort study performed in the community Neustadt am Rennsteig, Germany, which was quarantined from 22 March to 5 April after six SARS-CoV-2 cases were detected in the village's population. The SARS-CoV-2 outbreak comprised 51 cases and 3 deaths. The CoNAN study was performed from 13 May to 22 May 2020, 6 weeks after a SARS-CoV-2 outbreak. Results We enrolled a total of 626 participants (71% of the community population) for PCR and antibody testing in the study. All actual SARS-CoV-2 PCR tests were negative. Fifty-two out of 620 (8.4%) participants had antibodies against SARS-CoV-2 in at least two different assays. There were 38 participants with previously PCR-confirmed SARS-CoV-2 infection. Of those, only 19 (50%) displayed anti-SARS-CoV-2 antibodies. We also show that antibody-positive participants with symptoms compatible with a respiratory tract infection had significantly higher antibody levels then asymptomatic participants (EU-assay: median 2.9 versus 7.2 IgG-index, p 0.002; DS-assay: median 45.2 versus 143 AU/mL, p 0.002). Persisting viral replication was not detected. Conclusions Our data question the relevance and reliability of IgG antibody testing to detect past SARS-CoV-2 infections 6 weeks after an outbreak. We conclude that assessing immunity for SARS-CoV-2 infection should not rely on antibody tests alone.

There is increasing clinical evidence from observational studies, that combination therapy of daptomycin with rifampin is a valuable treatment option for biofilm-associated difficult to treat Staphylococcus aureus infections such as osteomyelitis, prosthetic joint infection and endocarditis. However, two studies analyzing a limited number of S. aureus isolates reported an antagonism of those two drugs questioning the benefit of this combination. To estimate the frequency of this possible antagonism, we performed in vitro checkerboard assays on 58 consecutive clinical isolates of S. aureus (MSSA n = 9, MRSA n = 49). We determined the fractional inhibitory concentration index (FICI) and the susceptible breakpoint index (SBPI). All isolates were characterized by a microprobe array detecting 336 different genes/alleles to ensure their non-clonal origin. For all isolates, the FICI was between 1.00 and 1.25 indicating additive effects for the daptomycin/rifampin combination. Neither antagonism nor synergism as defined by the FICI was found for any of the isolates. Based on these data, there is no evidence to advise against the daptomycin/rifampin combination therapy.

Infectious diseases are associated with disruption of host homeostasis. This can be triggered directly by pathogens or indirectly by host immune-driven resistance mechanisms. Disease tolerance is a defense strategy against infection that sustains host homeostasis, without exerting a direct negative impact on pathogens. The mechanisms governing disease tolerance encompass host metabolic responses that maintain vital homeostatic parameters within a range compatible with survival. Central to this defense strategy is the host's ability to sense and adapt to variations in nutrients, such as iron and glucose. Here we address how host responses regulating iron and glucose metabolism interact to establish disease tolerance and possibly modulate resistance to infection.

Background For patients with bacteraemia caused by methicillin-sensitive Staphylococcus aureus anti-staphylococcal penicillins (ASPs) or cefazolin are agents of choice. While ASPs are potentially nephrotoxic, cefazolin may be less effective in some S. aureus strains due to an inoculum effect. Objectives To perform a systematic literature review and meta-analysis assessing current evidence comparing cefazolin with ASPs for patients with S. aureus bacteraemia (SAB). Methods We searched MEDLINE, ISI Web of Science (Science Citation Index Expanded) and the Cochrane Database as well as clinicaltrials.gov from inception to 26 June 2018. All studies investigating the effects of cefazolin versus ASP in patients with methicillin-sensitive SAB were eligible for inclusion regardless of study design, publication status or language. Additional information was requested by direct author contact. A meta-analysis to estimate relative risks (RRs) with the corresponding 95% confidence intervals (CIs) was performed. Statistical heterogeneity was estimated using I2. The primary endpoint was 90-day all-cause mortality. The Newcastle–Ottawa Scale (NOS) and Grading of Recommendations Assessment, Development and Evaluation (GRADE) were used for study and data quality assessment. Results Fourteen non-randomized studies were included. Seven reported the primary endpoint (RR 0.71 (0.50, 1.02), low quality of evidence). Cefazolin treatment may be associated with lower 30-day mortality rates (RR 0.70 (0.54, 0.91), low quality of evidence) and less nephrotoxicity (RR 0.36 (0.21, 0.59), (low quality of evidence)). We are uncertain whether cefazolin and ASP differ regarding treatment failure/relapse as the quality of the evidence has been assessed as very low (RR of 0.84 (0.59, 1.18)). For patients with endocarditis (RR 0.71 (0.12, 4.05)) or abscesses (RR 1.17 (0.30, 4.63)), cefazolin treatment may be associated with equal 30-day and 90-day mortality (low quality of evidence). Conclusions Cefazolin seemed to be at least equally as effective as ASPs while being associated with less nephrotoxicity.

Background Currently, no suitable clinical marker for detection of septic immunosuppression is available. We aimed at identifying microRNAs that could serve as biomarkers of T-cell mediated immunoparalysis in sepsis. Methods RNA was isolated from purified T-cells or from whole blood cells obtained from septic patients and healthy volunteers. Differentially regulated miRNAs were identified by miRNA Microarray (n = 7). Validation was performed via qPCR (n = 31). Results T-cells of septic patients revealed characteristics of immunosuppression: Pro-inflammatory miR-150 and miR-342 were downregulated, whereas anti-inflammatory miR-15a, miR-16, miR-93, miR-143, miR-223 and miR-424 were upregulated. Assessment of T-cell effector status showed significantly reduced mRNA-levels of IL2, IL7R and ICOS, and increased levels of IL4, IL10 and TGF-β. The individual extent of immunosuppression differed markedly. MicroRNA-143, − 150 and − 223 independently indicated T-cell immunoparalysis and significantly correlated with patient’s IL7R-/ICOS-expression and SOFA-scores. In whole blood, composed of innate and adaptive immune cells, both traits of immunosuppression and hyperinflammation were detected. Importantly, miR-143 and miR-150 – both predominantly expressed in T-cells – retained strong power of discrimination also in whole blood samples. Conclusions These findings suggest miR-143 and miR-150 as promising markers for detection of T-cell immunosuppression in whole blood and may help to develop new approaches for miRNA-based diagnostic in sepsis. Electronic supplementary material The online version of this article (10.1186/s10020-018-0056-z) contains supplementary material, which is available to authorized users.

Development of organ dysfunction discriminates sepsis from uncomplicated infection. The paradigm shift implicated by the new sepsis-3 definition holds that initial impairment of any organ can pave the way for multiple organ dysfunction and death. Moreover, the role of the systemic inflammatory response, central element in previous sepsis definitions, has been questioned. Most strikingly, a so far largely underestimated defense mechanism of the host, i.e., "disease tolerance," which aims at maintaining host vitality without reducing pathogen load, has gained increasing attention. Here, we summarize evidence that a dysregulation of critical cellular signaling events, also in non-immune cells, might provide a conceptual framework for sepsis-induced dysfunction of parenchymal organs in the absence of significant cell death. We suggest that key signaling mediators, such as phosphoinositide 3-kinase, mechanistic target of rapamycin, and AMP-activated protein kinase, control the balance of damage and repair processes and thus determine the fate of affected organs and ultimately the host. Therapeutic targeting of these multifunctional signaling mediators requires cell-, tissue-, or organ-specific approaches. These novel strategies might allow stopping the domino-like damage to further organ systems and offer alternatives beyond the currently available strictly supportive therapeutic options.

Contains fulltext : 193456.pdf (Publisher’s version ) (Closed access) Recent investigations reveal memory-like adaptive responses of the innate immune system to sequential pathogen challenge. Of note, opposing effects that include both sensitization ('training') and desensitization ('tolerance') have been reported. While hitherto the nature of the pathogen was thought to be of prime importance, we propose that pathogen dose plays a key role in determining these opposing effects. Within this concept, training and tolerance of innate immune cells emerge as adaptive responses to increasing pathogen load. Furthermore, environmental stressors significantly impact the pathogen-induced responses of these innate immune cells. Therefore, we hypothesize that pathogens, like other stressors, provoke hormetic responses of the affected cells. This concept could explain the tight interplay of dose-related effects of pathogens and other stressors in infectious diseases.

Urosepsis is defined as a severe disease due to organ failure caused by a urinary tract infection. An empirical antibiotic therapy should be instigated within the first hour after diagnosis. Urine cultures and blood cultures should be performed before antibiotic treatment. Further diagnostics should be carried out at an early stage to enable an interventional focus control in the case of urinary tract obstruction or abscess formation, if necessary. Gram-negative pathogens are most frequently isolated. Extended spectrum beta-lactamase (ESBL) forming bacteria as a cause of urosepsis are increasing. Carbapenemase-forming Enterobacteriaceae, on the other hand, are still rare. The empirical treatment consists of a broad spectrum beta-lactam antibiotic. While piperacillin/tazobactam, carbapenems and the new cephalosporin/beta-lactamase inhibitor (BLI) combinations are given as monotherapy, cephalosporins should be combined with aminoglycosides (preferred) or fluoroquinolones. If a combination therapy is given, it should be de-escalated to a monotherapy after 48-72 h.

International audience; Sepsis is an often lethal syndrome resulting from maladaptive immune and metabolic responses to infection, compromising host homeostasis. Disease tolerance is a defense strategy against infection that preserves host homeostasis without exerting a direct negative impact on pathogens. Here, we demonstrate that induction of the iron-sequestering ferritin H chain (FTH) in response to polymicrobial infections is critical to establish disease tolerance to sepsis. The protective effect of FTH is exerted via a mechanism that counters iron-driven oxidative inhibition of the liver glucose-6-phosphatase (G6Pase), and in doing so, sustains endogenous glucose production via liver gluconeogenesis. This is required to prevent the development of hypoglycemia that otherwise compromises disease tolerance to sepsis. FTH overexpression or ferritin administration establish disease tolerance therapeutically. In conclusion, disease tolerance to sepsis relies on a crosstalk between adaptive responses controlling iron and glucose metabolism, required to maintain blood glucose within a physiologic range compatible with host survival.

Mitochondrial-derived reactive oxygen species have been deemed an important contributor in sepsis pathogenesis. We investigated whether two mitochondria-targeted antioxidants (mtAOX; SkQ1 and MitoTEMPO) improved long-term outcome, lessened inflammation, and improved organ homeostasis in polymicrobial murine sepsis. 3-month-old female CD-1 mice (n=90) underwent cecal ligation and puncture (CLP) and received SkQ1 (5 nmol/kg), MitoTEMPO (50 nmol/kg), or vehicle 5 times post-CLP. Separately, 52 SkQ1-treated CLP mice were sacrificed at 24 h and 48 h for additional endpoints. Neither MitoTEMPO nor SkQ1 exerted any protracted survival benefit. Conversely, SkQ1 exacerbated 28-day mortality by 29%. CLP induced release of 10 circulating cytokines, increased urea, ALT, and LDH, and decreased glucose but irrespectively of treatment. Similar occurred for CLP-induced lymphopenia/neutrophilia and the NO blood release. At 48 h post-CLP, dying mice had approximately 100-fold more CFUs in the spleen than survivors, but this was not SkQ1 related. At 48 h, macrophage and granulocyte counts increased in the peritoneal lavage but irrespectively of SkQ1. Similarly, hepatic mitophagy was not altered by SkQ1 at 24 h. The absence of survival benefit of mtAOX may be due to the extended treatment and/or a relatively moderate-risk-of-death CLP cohort. Long-term effect of mtAOX in abdominal sepsis appears different to sepsis/inflammation models arising from other body compartments.

Infectious diseases are a global health burden and remain associated with high social and economic impact. Treatment of affected patients largely relies on antimicrobial agents that act by directly targeting microbial replication. Despite the utility of host specific therapies having been assessed in previous clinical trials, such as targeting the immune response via modulating the cytokine release in sepsis, results have largely been frustrating and did not lead to the introduction of new therapeutic tools. In this article, we will discuss current evidence arguing that, by applying the concept of hormesis, already approved pharmacological agents could be used therapeutically to increase survival of patients with infectious disease via improving disease tolerance, a defense mechanism that decreases the extent of infection-associated tissue damage without directly targeting pathogenic microorganisms.

The deposited article is a prost-print version. This publication hasn't any creative commons license associated. This deposit is composed by the main article, and it hasn't any supplementary materials associated. Immune-driven resistance mechanisms are the prevailing host defense strategy against infection. By contrast, disease tolerance mechanisms limit disease severity by preventing tissue damage or ameliorating tissue function without interfering with pathogen load. We propose here that tissue damage control underlies many of the protective effects of disease tolerance. We explore the mechanisms of cellular adaptation that underlie tissue damage control in response to infection as well as sterile inflammation, integrating both stress and damage responses. Finally, we discuss the potential impact of targeting these mechanisms in the treatment of disease. Fundação para a Ciência e Tecnologia grants: (PTDC/SAU-TOX/116627/2010, HMSP-ICT/0022/2010, SFRH/BPD/44256/2008); European Commission 7th Framework grant: (ERC-2011-AdG. 294709-DAMAGECONTROL); Deutsche Forschungsgemeinschaft grant: (DFG WE 4971/3-1). info:eu-repo/semantics/publishedVersion

Heme oxygenase 1 (HO-1) is an essential enzyme induced by heme and multiple stimuli associated with critical illness. In humans, polymorphisms in the HMOX1 gene promoter may influence the magnitude of HO-1 expression. In many diseases including murine malaria, HO-1 induction produces protective anti-inflammatory effects, but observations from patients suggest these may be limited to a narrow range of HO-1 induction, prompting us to investigate the role of HO-1 in malaria infection. In 307 Gambian children with either severe or uncomplicated P. falciparum malaria, we characterized the associations of HMOX1 promoter polymorphisms, HMOX1 mRNA inducibility, HO-1 protein levels in leucocytes (flow cytometry), and plasma (ELISA) with disease severity. The (GT)n repeat polymorphism in the HMOX1 promoter was associated with HMOX1 mRNA expression in white blood cells in vitro, and with severe disease and death, while high HO-1 levels were associated with severe disease. Neutrophils were the main HO-1-expressing cells in peripheral blood, and HMOX1 mRNA expression was upregulated by heme-moieties of lysed erythrocytes. We provide mechanistic evidence that induction of HMOX1 expression in neutrophils potentiates the respiratory burst, and propose this may be part of the causal pathway explaining the association between short (GT)n repeats and increased disease severity in malaria and other critical illnesses. Our findings suggest a genetic predisposition to higher levels of HO-1 is associated with severe illness, and enhances the neutrophil burst leading to oxidative damage of endothelial cells. These add important information to the discussion about possible therapeutic manipulation of HO-1 in critically ill patients., Author Summary HO-1 is an important anti-inflammatory enzyme induced by several stimuli associated with critical illness. In humans, the amount of HO-1 produced is influenced by a genetic polymorphism in the gene promoter region. Using Plasmodium falciparum malaria that can cause a sepsis-like syndrome as an example, we characterize the associations between the (GT)n polymorphism, HO-1 protein levels and HMOX1-mRNA expression with severity of malaria in 307 Gambian children. Our results support the functionality of this polymorphism, demonstrate that P. falciparum infections increase HO-1 levels, and indicate that a genetic predisposition to strongly upregulate HO-1 is associated with severe forms of malaria and increased risk of dying. We identify neutrophils as the main HO-1-producing blood cells, and provide evidence that hemin-mediated induction of HMOX1 in neutrophils in vitro enhances the oxidative burst. In this way sequestered neutrophils may contribute to oxidative damage of endothelial cells, which may be part of a causal pathway explaining the association between short (GT)n repeats and increased disease severity. Our findings imply that the beneficial effects of HO-1 may be limited to a narrow window of concentrations, which should be born in mind when considering the therapeutic potential of manipulating HO-1 induction in critically ill patients.