Characterization of Pathogenic Sepsis Etiologies and Patient Profiles: A Novel Approach to Triage and Treatment

LPS-induced systemic inflammation is suppressed by the PDZ motif peptide of ZO-1 via regulation of macrophage M1/M2 polarization

The gram-negative bacterium lipopolysaccharide (LPS) is frequently administered to generate models of systemic inflammation. However, there are several side effects and no effective treatment for LPS-induced systemic inflammation. PEGylated PDZ peptide based on zonula occludens-1 (ZO-1) was analyzed for its effects on systemic inflammation induced by LPS. PDZ peptide administration led to the restoration of tissue injuries (kidney, liver, and lung) and prevented alterations in biochemical plasma markers. The production of pro-inflammatory cytokines was significantly decreased in the plasma and lung BALF in the PDZ-administered mice. Flow cytometry analysis revealed the PDZ peptide significantly inhibited inflammation, mainly by decreasing the population of M1 macrophages, and neutrophils (immature and mature), and increasing M2 macrophages. Using RNA sequencing analysis, the expression levels of the NF-κB-related proteins were lower in PDZ-treated cells than in LPS-treated cells. In addition, wild-type PDZ peptide significantly increased mitochondrial membrane integrity and decreased LPS-induced mitochondria fission. Interestingly, PDZ peptide dramatically could reduce LPS-induced NF-κB signaling, ROS production, and the expression of M1 macrophage marker proteins, but increased the expression of M2 macrophage marker proteins. These results indicated that PEGylated PDZ peptide inhibits LPS-induced systemic inflammation, reducing tissue injuries and reestablishing homeostasis, and may be a therapeutic candidate against systemic inflammation.

Protocol for inducing monomicrobial sepsis in mice with uropathogenic E. coli

Bacterial infections are the primary cause of pathogenic sepsis. An uropathogenic E. coli (UPEC) model of monomicrobial sepsis represents a useful tool for interrogating the host immune response to this pathogen. Here, we present a protocol for inducing monomicrobial sepsis in mice using UPEC. We describe steps for preparing the bacteria, delivering UPEC into mice, and monitoring the mice post-infection. We then detail procedures for measuring cytokine response and detecting immune cell subsets using flow cytometry. For complete details on the use and execution of this protocol, please refer to Martin et al.1.

The Role of Serum Albumin and Secretory Phospholipase A2 in Sepsis

Sepsis is caused by a dysregulated host response to an infection that leads to cascading cell death and eventually organ failure. In this study, the role of inflammatory response serum secretory phospholipase A2 (sPLA2) and albumin in sepsis was investigated by determining the activities of the two proteins in serial serum samples collected on different days from patients with sepsis after enrollment in the permissive underfeeding versus standard enteral feeding protocols in an intensive care unit. Serum sPLA2 and albumin showed an inverse relationship with increasing sPLA2 activity and decreasing albumin membrane-binding activity in patients with evolving complications of sepsis. The activities of sPLA2 and albumin returned to normal values more rapidly in the permissive underfeeding group than in the standard enteral feeding group. The inverse sPLA2-albumin activity relationship suggests a complex interplay between these two proteins and a regulatory mechanism underlying cell membrane phospholipid homeostasis in sepsis. The decreased albumin-membrane binding activity in patients' serum was due to its fatty acid-binding sites occupied by pre-bound fatty acids that might alter albumin's structure, binding capacities, and essential functions. The sPLA2-albumin dual serum assays may be useful in determining whether nutritional intervention effectively supports the more rapid recovery of appropriate immune responses in critically ill patients with sepsis.

Fighting sepsis-induced liver damage with biosynthesized silver nanoparticles

Sepsis is a potentially fatal disease that arises from an infection and is characterized by an uncontrolled immune system reaction. Global healthcare systems bear a heavy financial burden from treating sepsis. This study aimed to provide information on the effective properties of silver nanoparticles derived from pomegranate peel extract (P-AgNP) against sepsis-induced hepatic injury. P-AgNPs were spherical with a diameter of ~19 nm. The animals were placed into four groups, each with seven rats. Group 1 functioned as the control group, receiving only saline for 7 days. Group 2 received only P-AgNPs at a dose of 20 mg/kg. To induce sepsis, groups 3 and 4 were given an intraperitoneal injection of 200 mg/mL cecal slurry. Sixty min later, group 4 was given 20 mg/kg of P-AgNPs daily for 7 days. The concentrations of reduced glutathione, nitric oxide, lipid peroxidation, and superoxide dismutase in liver homogenate were measured to determine the oxidative status. In addition, enzyme activities (alanine aminotransferase, aspartate amino transferase, and alkaline phosphatase) were measured. Furthermore, we investigated the histological changes, immunohistochemical expression of nuclear factor-κB, and mRNA levels of IL1β, IL-6, TNF-α, Bax, BCl2, and Casp-3. P-AgNPs functioned as regulators in a sepsis model, successfully controlling altered gene expression. Following treatment, P-AgNPs improved tion and oxidative state, indicating a role in sepsis management. Based on our findings, we conclude that P-AgNPs have antioxidant activity and may be useful in preventing sepsis-induced liver inflammation, oxidative damage, and apoptosis. RESEARCH HIGHLIGHTS: Pomegranate peel-derived silver nanoparticles (P-AgNPs) enhanced liver function and oxidative state in rats with sepsis-induced hepatic damage. P-AgNPs reduced oxidative stress and liver inflammation via regulating inflammatory and apoptotic gene expression. P-AgNPs enhanced liver enzyme activities, histological structure, and immunohistochemistry expression of nuclear factor-κB.

Antimicrobial Resistance in Sepsis Cases Due to Escherichia coli and Klebsiella pneumoniae: Pre-Pandemic Insights from a Single Center in Southwestern Romania

Sepsis is an uncontrolled reaction of the body to an infection, and if not effectively treated, it can progress to septic shock, multiple organ failure, and ultimately, death.

OBJECTIVE

To determine the resistance profile of Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) strains isolated in sepsis cases diagnosed at the Infectious Diseases Clinic in Craiova, Romania.

METHODS

The bacteria responsible for sepsis cases were identified using the Vitek 2 Systems version 06.01, which was then employed to assess their antimicrobial susceptibility (Global CLSI and Phenotypic 2017).

RESULTS

We have identified 989 patients diagnosed with bacterial sepsis. Among these, 953 cases were caused by Gram-negative rods, with 415 attributed to E. coli and 278 to K. pneumoniae. High levels of resistance to ampicillin were recorded for E. coli strains isolated in sepsis cases (64.6%); adding sulbactam lowers the level of resistance to 41.8%. Resistance to 3rd generation cephalosporins varied between 7.47 and 14.6% and another 3.41 to 11.1% are dose-dependent susceptibility strains. Resistance to carbapenems (i.e., ertapenem, meropenem) is low-2.18-2.42%. More than 95% of the tested K. pneumoniae strains were resistant to ampicillin and adding sulbactam as a β-lactamase inhibitor only halves that level. Resistance to 3rd generation cephalosporins varied between 20.7% and 22.5%; resistance levels for K. pneumoniae were notably higher than those for E. coli. Over 95% of K. pneumoniae strains showed resistance to ampicillin, and resistance to 3rd generation cephalosporins varied between 20.7% and 22.5%. Additionally, K. pneumoniae exhibited higher resistance to carbapenems (13.7-19.5%) compared to E. coli (2.18-2.42%).

CONCLUSIONS

Antimicrobial resistance levels are generally lower than continental and national data, except for ampicillin and carbapenems (meropenem and ertapenem). K. pneumoniae strains are significantly more resistant than E. coli strains.

Lipid Fraction from Agaricus brasiliensis as a Potential Therapeutic Agent for Lethal Sepsis in Mice

Sepsis is a potentially fatal clinical condition that results from an immune imbalance in the host during an infection. It presents systemic alterations due to excessive activation of pro-inflammatory mediators that contribute to inflammation, formation of reactive species, and tissue damage. Anti-inflammatory mediators are then extensively activated to regulate this process, leading to immune exhaustion and, consequently, immunosuppression of the host. Considering the biological activities of the nutraceutical Agaricus brasiliensis (A. brasiliensis), such as immunomodulatory, antioxidant, and antitumor activities, the present study investigated the therapeutic potential of the lipid fraction of A. brasiliensis (LF) in a model of lethal sepsis in mice (Mus musculus), induced by cecal ligation and perforation (CLP). The results showed that treatment of septic animals with LF or LF associated with ertapenem (LF-Erta) reduced systemic inflammation, promoting improvement in clinical parameters and increased survival. The data show a reduction in pro-inflammatory and oxidative stress markers, regulation of the anti-inflammatory response and oxidizing agents, and increased bacterial clearance in the peritoneal cavity and liver. Thus, it can be concluded that LF as a treatment, and in conjunction with antibiotic therapy, has shown promising effects as a hepatoprotective, antioxidant, antimicrobial, and immunomodulatory agent.

Transcriptional markers classifying Escherichia coli and Staphylococcus aureus induced sepsis in adults: A data-driven approach

Sepsis is a life-threatening condition mainly caused by gram-negative and gram-positive bacteria. Understanding the type of causative agent in the early stages is essential for precise antibiotic therapy. This study sought to identify a host gene set capable of distinguishing between sepsis induced by gram-negative bacteria; Escherichia coli and gram-positive bacteria; Staphylococcus aureus in community-onset adult patients. In the present study, microarray expression information was used to apply the Least Absolute Shrinkage and Selection Operator (Lasso) technique to select the predictive gene set for classifying sepsis induced by E. coli or S. aureus pathogens. We identified 25 predictive genes, including LILRA5 and TNFAIP6, which had previously been associated with sepsis in other research. Using these genes, we trained a logistic regression classifier to distinguish whether a sample contains an E. coli or S. aureus infection or belongs to a healthy control group, and subsequently assessed its performance. The classifier achieved an Area Under the Curve (AUC) of 0.96 for E. coli and 0.98 for S. aureus-induced sepsis, and perfect discrimination (AUC of 1) for healthy controls from the other conditions in a 10-fold cross-validation. The genes demonstrated an AUC of 0.75 in distinguishing between sepsis patients with E. coli and S. aureus pathogens. These findings were further confirmed in two distinct independent validation datasets which gave high prediction AUC ranging from 0.72-0.87 and 0.62 in distinguishing three groups of participants and two groups of patients respectively. These genes were significantly enriched in the immune system, cytokine signaling in immune system, innate immune system, and interferon signaling. Transcriptional patterns in blood can differentiate patients with E. coli-induced sepsis from those with S. aureus-induced sepsis. These diagnostic markers, upon validation in larger trials, may serve as a foundation for a reliable differential diagnostics assay.

Investigating the efficacy of dapsone in treating sepsis induced by cecal ligation and puncture surgery in male mice

Sepsis is a life-threatening condition caused by the body's response to an infection. Dapsone is a sulfone with antibiotic properties, and experimental evidence suggests it has significant anti-inflammatory and anti-oxidative stress effects. The objective of this study was to investigate the efficacy of dapsone in mice after CLP (cecal ligation and puncture) surgery, which is a model for inducing sepsis. The study divided animals into five groups: CLP, sham, and three groups receiving different doses of dapsone (0.5, 1, 2 mg/kg). Sepsis was induced through CLP surgery, followed by dapsone administration. In each group, half of the mice were used to evaluate levels of various markers and pathological changes at 24 h post-CLP, while the other half was used to record the mortality rates within 96 h. The results showed that single-dose administration of dapsone at (0.5, 1, 2 mg/kg) after CLP surgery improved survival compared to the CLP group. Dapsone was also associated with a significant reduction in pro-inflammatory cytokines TNF-α, IL-1β, IL-6, NO, and MPO, as well as lactate and creatinine serum levels. However, dapsone did not have a significant effect on urea serum levels. In conclusion, the data suggest that dapsone treatment leads to increased survival in septic mice after CLP, and due to its ability to reduce TNF-α, IL-1β, IL-6, MPO, and lactate levels, it has anti-inflammatory effects in sepsis. The sepsis treatment with dapsone in mice protects against inflammation and oxidative stress.

Hospital Acquired Sepsis, Disease Prevalence, and Recent Advances in Sepsis Mitigation

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, commonly associated with nosocomial transmission. Gram-negative bacterial species are particularly problematic due to the release of the lipopolysaccharide toxins upon cell death. The lipopolysaccharide toxin of E. coli has a greater immunogenic potential than that of other Gram-negative bacteria. The resultant dysregulation of the immune system is associated with organ failure and mortality, with pregnant women, ICU patients, and neonates being particularly vulnerable. Additionally, sepsis recovery patients have an increased risk of re-hospitalisation, chronic illness, co-morbidities, organ damage/failure, and a reduced life expectancy. The emergence and increasing prevalence of antimicrobial resistance in bacterial and fungal species has impacted the treatment of sepsis patients, leading to increasing mortality rates. Multidrug resistant pathogens including vancomycin-resistant Enterococcus, beta lactam-resistant Klebsiella, and carbapenem-resistant Acinetobacter species are associated with an increased risk of mortality. To improve the prognosis of sepsis patients, predominantly high-risk neonates, advances must be made in the early diagnosis, triage, and control of sepsis. The identification of suitable biomarkers and biomarker combinations, coupled with machine learning and artificial intelligence, show promise in early detection protocols. Rapid diagnosis of sepsis in patients is essential to inform on clinical treatment, especially with resistant infectious agents. This timely review aims to discuss sepsis prevalence, aetiology, and recent advances towards disease mitigation and control.

In response to bacteria, neutrophils release extracellular vesicles capable of initiating thrombin generation through DNA-dependent and independent pathways

Neutrophils release extracellular vesicles (EVs) and some subsets of neutrophil-derived EVs are procoagulant. In response to S. aureus, neutrophils produce EVs that associate electrostatically with neutrophil extracellular traps (NETs). DNA in NETs is procoagulant, but whether neutrophil EVs produced during bacterial challenge have similar activity is unknown. Given that EV activity is agonist- and cell-type dependent and coagulation contributes to sepsis, we hypothesized that sepsis-causing bacteria increase production of neutrophil-derived EVs, as well as EV-associated DNA, and intact EVs and DNA cause coagulation. We recovered EVs from neutrophils challenged with S. aureus (SA), S. epidermidis (SE), E. coli (EC), and P. aeruginosa (PA), and measured associated DNA and procoagulant activity. EVs from SA-challenged neutrophils (SA-EVs), which were previously characterized, displayed dose-dependent procoagulant activity as measured by thrombin generation (TG) in platelet-poor plasma. EV lysis and DNase treatment reduced TG by 90% and 37%, respectively. SE, EC, and PA also increased EV production and EV-associated extracellular DNA, and these EVs were also procoagulant. Compared to spontaneously released EVs, which demonstrated some ability to amplify Factor XII-dependent coagulation in the presence of an activator, only EVs produced in response to bacteria could initiate the pathway. SA-EVs and SE-EVs had more surface-associated DNA than EC-EVs and PA-EVs, and SA-EVs and SE-EVs contributed to initiation and amplification of TG in a DNA-dependent manner. However, DNA on EC- or PA-EVs played no role, suggesting that neutrophils release procoagulant EVs which can activate the coagulation cascade through both DNA-dependent and independent mechanisms.

Sepsis-Related Lung Injury and the Complication of Extrapulmonary Pneumococcal Pneumonia

Globally, sepsis and pneumonia account for significant mortality and morbidity. A complex interplay of immune-molecular pathways underlies both sepsis and pneumonia, resulting in similar and overlapping disease characteristics. Sepsis could result from unmanaged pneumonia. Similarly, sepsis patients have pneumonia as a common complication in the intensive care unit. A significant percentage of pneumonia is misdiagnosed as septic shock. Therefore, our knowledge of the clinical relationship between pneumonia and sepsis is imperative to the proper management of these syndromes. Regarding pathogenesis and etiology, pneumococcus is one of the leading pathogens implicated in both pneumonia and sepsis syndromes. Growing evidence suggests that pneumococcal pneumonia can potentially disseminate and consequently induce systemic inflammation and severe sepsis. Streptococcus pneumoniae could potentially exploit the function of dendritic cells (DCs) to facilitate bacterial dissemination. This highlights the importance of pathogen-immune cell crosstalk in the pathophysiology of sepsis and pneumonia. The role of DCs in pneumococcal infections and sepsis is not well understood. Therefore, studying the immunologic crosstalk between pneumococcus and host immune mediators is crucial to elucidating the pathophysiology of pneumonia-induced lung injury and sepsis. This knowledge would help mitigate clinical diagnosis and management challenges.

Using the Traditional Ex Vivo Whole Blood Model to Discriminate Bacteria by Their Inducible Host Responses

Whole blood models are rapid and versatile for determining immune responses to inflammatory and infectious stimuli, but they have not been used for bacterial discrimination. Staphylococcus aureus, S. epidermidis and Escherichia coli are the most common causes of invasive disease, and rapid testing strategies utilising host responses remain elusive. Currently, immune responses can only discriminate between bacterial 'domains' (fungi, bacteria and viruses), and very few studies can use immune responses to discriminate bacteria at the species and strain level. Here, whole blood was used to investigate the relationship between host responses and bacterial strains. Results confirmed unique temporal profiles for the 10 parameters studied: IL-6, MIP-1α, MIP-3α, IL-10, resistin, phagocytosis, S100A8, S100A8/A9, C5a and TF3. Pairwise analysis confirmed that IL-6, resistin, phagocytosis, C5a and S100A8/A9 could be used in a discrimination scheme to identify to the strain level. Linear discriminant analysis (LDA) confirmed that (i) IL-6, MIP-3α and TF3 could predict genera with 95% accuracy; (ii) IL-6, phagocytosis, resistin and TF3 could predict species at 90% accuracy and (iii) phagocytosis, S100A8 and IL-10 predicted strain at 40% accuracy. These data are important because they confirm the proof of concept that host biomarker panels could be used to identify bacterial pathogens.

Exploring the role of antioxidants in sepsis-associated oxidative stress: a comprehensive review

Sepsis is a potentially fatal condition characterized by organ dysfunction caused by an imbalanced immune response to infection. Although an increased inflammatory response significantly contributes to the pathogenesis of sepsis, several molecular mechanisms underlying the progression of sepsis are associated with increased cellular reactive oxygen species (ROS) generation and exhausted antioxidant pathways. This review article provides a comprehensive overview of the involvement of ROS in the pathophysiology of sepsis and the potential application of antioxidants with antimicrobial properties as an adjunct to primary therapies (fluid and antibiotic therapies) against sepsis. This article delves into the advantages and disadvantages associated with the utilization of antioxidants in the therapeutic approach to sepsis, which has been explored in a variety of animal models and clinical trials. While the application of antioxidants has been suggested as a potential therapy to suppress the immune response in cases where an intensified inflammatory reaction occurs, the use of multiple antioxidant agents can be beneficial as they can act additively or synergistically on different pathways, thereby enhancing the antioxidant defense. Furthermore, the utilization of immunoadjuvant therapy, specifically in septic patients displaying immunosuppressive tendencies, represents a promising advancement in sepsis therapy.

Kazachstania pintolopesii in Blood and Intestinal Wall of Macrophage-Depleted Mice with Cecal Ligation and Puncture, the Control of Fungi by Macrophages during Sepsis

Although macrophage depletion is a possible emerging therapeutic strategy for osteoporosis and melanoma, the lack of macrophage functions can lead to inappropriate microbial control, especially the regulation of intestinal microbiota. Cecal ligation and puncture (CLP) sepsis was performed in regular mice and in mice with clodronate-induced macrophage depletion. Macrophage depletion significantly increased the mortality and severity of sepsis-CLP mice, partly through the increased fecal Ascomycota, especially Kazachstania pintolopesii, with polymicrobialbacteremia (Klebsiella pneumoniae, Enterococcus faecalis, and Acinetobacter radioresistens). Indeed, macrophage depletion with sepsis facilitated gut dysbiosis that directly affected gut permeability as yeast cells were located and hidden in the colon crypts. To determine the interactions of fungal molecules on bacterial abundance, the heat-kill lysate of fungi (K. pintolopesii and C. albicans) and purified (1→3)-β-d-glucan (BG; a major component of the fungal cell wall) were incubated with bacteria that were isolated from the blood of macrophage-depleted mice. There was enhanced cytokine production of enterocytes (Caco-2) after the incubation of the lysate of K. pintolopesii (isolated from sepsis mice), the lysate of C. albicans (extracted from sepsis patients), and BG, together with bacterial lysate. These data support a possible influence of fungi in worsening sepsis severity. In conclusion, macrophage depletion enhanced K. pintolopesii in feces, causing the overgrowth of fecal pathogenic bacteria and inducing a gut permeability defect that additively worsened sepsis severity. Hence, the fecal fungus could be spontaneously elevated and altered in response to macrophage-depleted therapy, which might be associated with sepsis severity.

P2X7 receptor antagonist A-438079 alleviates oxidative stress of lung in LPS-induced septic rats

Sepsis is a deadly systemic inflammatory response of the body against infection resulting in immune response, cell differentiation and organ damage. Endotoxemia is one of the causes of sepsis-related acute respiratory distress and respiratory burst is an important generator of oxidants. Inflammation may be aggravated by overexpression of ATP-gated purinergic receptors (i.e., P2X7R) following cell damage. We aimed to evaluate the effects of P2X7R antagonist A-438079 on lung oxidative status and the receptor expression in endotoxemia of sepsis. Rats were subjected to sepsis by E. coli lipopolysaccharide (LPS) and treated with 15 mg/kg A-438079. The increase in circulatory IL-1β and IL-8 concentrations in LPS group confirmed the systemic inflammatory response to endotoxemia compared with Control groups (p < 0.001). Besides, there was an increase in P2X7R expression in lung tissue after LPS administration. Compared with Control groups, there were significant increases in the values of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) (p < 0.001), and myeloperoxidase (MPO) (p < 0.05) in lung tissue of LPS group. P2X7R expression in lung and IL-1β level in blood did not increase in LPS + A-438079 group. A-438079 decreased the lung levels of MDA, GSH, CAT and SOD (p < 0.001), and MPO (p < 0.01) in septic rats. As a result, administration of pathogen-associated LPS led to increased P2X7R expression into lung tissue and elevated lipid peroxidation product MDA with regard to oxidative damage. The P2X7R antagonist A-438079 alleviated the oxidative stress of lung with a balance of tissue oxidant/antioxidant factors in experimental sepsis in rats.

CD115+ monocytes protect microbially experienced mice against E. coli-induced sepsis

Uropathogenic E. coli (UPEC) is a primary organism responsible for urinary tract infections and a common cause of sepsis. Microbially experienced laboratory mice, generated by cohousing with pet store mice, exhibit increased morbidity and mortality to polymicrobial sepsis or lipopolysaccharide challenge. By contrast, cohoused mice display significant resistance, compared with specific pathogen-free mice, to a monomicrobial sepsis model using UPEC. CD115+ monocytes mediate protection in the cohoused mice, as depletion of these cells leads to increased mortality and UPEC pathogen burden. Further study of the cohoused mice reveals increased TNF-α production by monocytes, a skewing toward Ly6ChiCD115+ "classical" monocytes, and enhanced egress of Ly6ChiCD115+ monocytes from the bone marrow. Analysis of cohoused bone marrow also finds increased frequency and number of myeloid multipotent progenitor cells. These results show that a history of microbial exposure impacts innate immunity in mice, which can have important implications for the preclinical study of sepsis.

Prevalence and antibiotic resistance pattern of bacteria from sepsis suspected neonates at St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia

BACKGROUND

Neonatal sepsis is the major cause of neonatal mortality and morbidity, especially in low and middle-income countries. Continuous monitoring of pathogens and their antibiotic resistance pattern is crucial for managing neonatal sepsis. This study aimed to determine neonatal sepsis due to bacteria, antibiotic resistance patterns, associated risk factors and patient outcomes at St. Paul's Hospital Millennium Medical College.

METHOD

An institutional-based cross-sectional study was conducted on 400 neonates suspected of sepsis at St. Paul's Hospital Millennium Medical College from March 2020 to July 2020. A questionnaire was used to collect socio-demographic information, clinical parameters and potential risk factors from study participants. About 2ml of blood was drawn aseptically and inoculated into Tryptone Soya Broth at the patient's bedside. Bacterial identification was performed by using standard microbiological techniques. The disk diffusion method was used to determine the antibiotic susceptibility patterns of each isolated bacteria. Data entry and analysis were done using Statistical Package for Social Sciences (SPSS) version 20 software. Bivariate and multivariable logistic regressions were used to assess associated risk factors of neonatal sepsis. A p-value less than 0.05 was considered statically significant with a 95% confidence interval.

RESULTS

The overall prevalence of neonatal septicemia was 21% (84/400). Of these, 67 (79.8%) and 17 (20.2%) were gram-negative and gram-positive bacteria, respectively. Klebsiella spp, 37 (44%), E. coli 19 (21.6%) and Coagulase negative Staphylococci 13 (15.47%) were the leading cause of neonatal sepsis. Ciprofloxacin and amikacin were the most effective antibiotics for gram-negative and gram-positive bacteria. Multidrug resistance was observed in 84% of the bacterial isolates. Low birth weight and preterm were associated with neonatal septicemia (AOR = 49.90, 95% CI = 15.14-123.081, P = 0.002) and (AOR = 18.20, 95% CI = 6.835-27.541, P = 0.004) respectively.

CONCLUSION

Klebsiella spp and E. coli were frequently isolated bacteria in our study. The proportion of multidrug-resistance was significantly high. Most isolated bacteria were resistant to ampicillin, ceftazidime, cefotaxime and gentamycin, which indicates the necessity of continuous evaluation of antibiotic resistance rate.

Neutrophil extracellular traps formation and clearance is enhanced in fever and attenuated in hypothermia

Fever and hypothermia represent two opposite strategies for fighting systemic inflammation. Fever results in immune activation; hypothermia is associated with energy conservation. Systemic Inflammatory Response Syndrome (SIRS) remains a significant cause of mortality worldwide. SIRS can lead to a broad spectrum of clinical symptoms but importantly, patients can develop fever or hypothermia. During infection, polymorphonuclear cells (PMNs) such as neutrophils prevent pathogen dissemination through the formation of neutrophil extracellular traps (NETs) that ensnare and kill bacteria. However, when dysregulated, NETs also promote host tissue damage. Herein, we tested the hypothesis that temperature modulates NETs homeostasis in response to infection and inflammation. NETs formation was studied in response to infectious (Escherichia coli, Staphylococcus aureus) and sterile (mitochondria) agents. When compared to body temperature (37°C), NETs formation increased at 40°C; interestingly, the response was stunted at 35°C and 42°C. While CD16+ CD49d+ PMNs represent a small proportion of the neutrophil population, they formed ~45-85% of NETs irrespective of temperature. Temperature increased formyl peptide receptor 1 (FPR1) expression to a differential extent in CD16+ CD49d- vs. CD49d+ PMNSs, suggesting further complexity to neutrophil function in hypo/hyperthermic conditions. The capacity of NETs to induce Toll-like receptor 9 (TLR9)-mediated NF-κB activation was found to be temperature independent. Interestingly, NET degradation was enhanced at higher temperatures, which corresponded with greater plasma DNase activity in response to temperature increase. Collectively, our observations indicate that NETs formation and clearance are enhanced at 40°C whilst temperatures of 35°C and 42°C attenuate this response. Targeting PMN-driven immunity may represent new venues for intervention in pathological inflammation.

Identifying Effective Biomarkers for Accurate Pancreatic Cancer Prognosis Using Statistical Machine Learning

Pancreatic cancer (PC) has one of the lowest survival rates among all major types of cancer. Consequently, it is one of the leading causes of mortality worldwide. Serum biomarkers historically correlate well with the early prognosis of post-surgical complications of PC. However, attempts to identify an effective biomarker panel for the successful prognosis of PC were almost non-existent in the current literature. The current study investigated the roles of various serum biomarkers including carbohydrate antigen 19-9 (CA19-9), chemokine (C-X-C motif) ligand 8 (CXCL-8), procalcitonin (PCT), and other relevant clinical data for identifying PC progression, classified into sepsis, recurrence, and other post-surgical complications, among PC patients. The most relevant biochemical and clinical markers for PC prognosis were identified using a random-forest-powered feature elimination method. Using this informative biomarker panel, the selected machine-learning (ML) classification models demonstrated highly accurate results for classifying PC patients into three complication groups on independent test data. The superiority of the combined biomarker panel (Max AUC-ROC = 100%) was further established over using CA19-9 features exclusively (Max AUC-ROC = 75%) for the task of classifying PC progression. This novel study demonstrates the effectiveness of the combined biomarker panel in successfully diagnosing PC progression and other relevant complications among Egyptian PC survivors.

Lipid oxidation dysregulation: an emerging player in the pathophysiology of sepsis

Sepsis is a life-threatening organ dysfunction caused by abnormal host response to infection. Millions of people are affected annually worldwide. Derangement of the inflammatory response is crucial in sepsis pathogenesis. However, metabolic, coagulation, and thermoregulatory alterations also occur in patients with sepsis. Fatty acid mobilization and oxidation changes may assume the role of a protagonist in sepsis pathogenesis. Lipid oxidation and free fatty acids (FFAs) are potentially valuable markers for sepsis diagnosis and prognosis. Herein, we discuss inflammatory and metabolic dysfunction during sepsis, focusing on fatty acid oxidation (FAO) alterations in the liver and muscle (skeletal and cardiac) and their implications in sepsis development.

Monocyte distribution width (MDW) in sepsis

Sepsis is a life-threatening syndrome due to a dysregulated host response to infection, which can be caused by bacterial, viral, or fungal infection. Thus, it is crucial to know how the different microorganisms influence the levels of a biomarker. In the last decade, monocyte distribution width (MDW) has emerged as a promising sepsis biomarker, especially in acute settings, such as the Emergency Department and Intensive Care Unit. In this article, we explore the relationship between MDW and the different pathogens causing infection. Noteworthy, MDW is not a biological molecule, but it is calculated by a mathematical formula based on monocyte characteristics. Monocytes represent the first line defence against microorganisms and undergo activation upon infection, independently from the invading pathogen. According to the knowledge on the biomarker biology and the few literatures evidence, MDW may be considered a biomarker of sepsis, independent of the causative pathogen. However, further investigations are warranted before drawing definite conclusion.

Retinoic Acid-Induced Regulation of Inflammatory Pathways Is a Potential Sepsis Treatment

Sepsis is among the most dangerous known diseases, resulting from the dysregulation of the innate immune system in a process that is characterized largely by proinflammatory cytokines. It manifests as an excessive immune response to a pathogen and often leads to life-threatening complications such as shock and multiple-organ failure. Within the past several decades, much progress has been made to better understand the pathophysiology of sepsis and improve treatment. However, the average case-fatality rate for sepsis remains high. Current anti-inflammatory therapeutics for sepsis are not effective for use as first-line treatments. Focusing on all-trans-retinoic acid (RA), or activated vitamin A, as a novel anti-inflammatory agent, we have shown both in vitro and in vivo that RA decreases the production of proinflammatory cytokines. In vitro studies using mouse RAW 264.7 macrophages show that RA decreases tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) and increases mitogen-activated protein kinase phosphatase 1 (MKP-1). RA treatment was also associated with the reduced phosphorylation of key inflammatory signaling proteins. Using a lipopolysaccharide and cecal slurry sepsis model, we found that RA significantly reduced mortality rates in mice, downregulated proinflammatory cytokine production, decreased neutrophil infiltration into lung tissue, and reduced the destructive lung histopathology typically seen in sepsis. We propose that RA may increase the function of native regulatory pathways and serve as a novel treatment for sepsis.

Differentiation of Fungal, Viral, and Bacterial Sepsis using Multimodal Deep Learning

Sepsis is a major cause of morbidity and mortality worldwide, and is caused by bacterial infection in a majority of cases. However, fungal sepsis often carries a higher mortality rate both due to its prevalence in immunocompromised patients as well as delayed recognition. Using chest x-rays, associated radiology reports, and structured patient data from the MIMIC-IV clinical dataset, the authors present a machine learning methodology to differentiate between bacterial, fungal, and viral sepsis. Model performance shows AUCs of 0.81, 0.83, 0.79 for detecting bacterial, fungal, and viral sepsis respectively, with best performance achieved using embeddings from image reports and structured clinical data. By improving early detection of an often missed causative septic agent, predictive models could facilitate earlier treatment of non-bacterial sepsis with resultant associated mortality reduction.

Antioxidant, Antiapoptotic, and Anti-Inflammatory Effects of Hesperetin in a Mouse Model of Lipopolysaccharide-Induced Acute Kidney Injury

Sepsis is a severe inflammatory condition that can cause organ dysfunction, including acute kidney injury (AKI). Hesperetin is a flavonoid aglycone that has potent antioxidant and anti-inflammatory properties. However, the effect of hesperetin on septic AKI has not yet been fully investigated. This study examined whether hesperetin has a renoprotective effect on lipopolysaccharide (LPS)-induced septic AKI. Hesperetin treatment ameliorated histological abnormalities and renal dysfunction in LPS-injected mice. Mechanistically, hesperetin attenuated LPS-induced oxidative stress, as evidenced by the suppression of lipid and DNA oxidation. This beneficial effect of hesperetin was accompanied by downregulation of the pro-oxidant NADPH oxidase 4, restoration of glutathione levels, and activation of antioxidant enzymes. This flavonoid compound also inhibited apoptotic cell death via suppression of p53-dependent caspase-3 pathway. Furthermore, hesperetin alleviated Toll-like receptor 4-mediated cytokine production and macrophage infiltration. Our findings suggest that hesperetin ameliorates LPS-induced renal structural and functional injury through suppressing oxidative stress, apoptosis, and inflammation.

How Different Pathologies Are Affected by IFIT Expression

The type-I interferon (IFN) system represents the first line of defense against viral pathogens. Recognition of the virus initiates complex signaling pathways that result in the transcriptional induction of IFNs, which are then secreted. Secreted IFNs stimulate nearby cells and result in the production of numerous proinflammatory cytokines and antiviral factors. Of particular note, IFN-induced tetratricopeptide repeat (IFIT) proteins have been thoroughly studied because of their antiviral activity against different viral pathogens. Although classically studied as an antiviral protein, IFIT expression has recently been investigated in the context of nonviral pathologies, such as cancer and sepsis. In oral squamous cell carcinoma (OSCC), IFIT1 and IFIT3 promote metastasis, while IFIT2 exhibits the opposite effect. The role of IFIT proteins during bacterial/fungal sepsis is still under investigation, with studies showing conflicting roles for IFIT2 in disease severity. In the setting of viral sepsis, IFIT proteins play a key role in clearing viral infection. As a result, many viral pathogens, such as SARS-CoV-2, employ mechanisms to inhibit the type-I IFN system and promote viral replication. In cancers that are characterized by upregulated IFIT proteins, medications that decrease IFIT expression may reduce metastasis and improve survival rates. Likewise, in cases of viral sepsis, therapeutics that increase IFIT expression may improve viral clearance and reduce the risk of septic shock. By understanding the effect of IFIT proteins in different pathologies, novel therapeutics can be developed to halt disease progression.

Premorbid use of selective beta-blockers improves sepsis incidence and course: Human cohort and animal model studies

Introduction

Beta-blockers are widely prescribed to manage hypertension and cardiovascular diseases and have been suggested as an attractive therapy to improve the prognosis of sepsis. Herein, we investigated the potential benefits of premorbid selective beta-blocker use in sepsis with a real-world database and explored the underlying mechanism by in vivo and in vitro experiments.

Methods

A total of 64,070 sepsis patients and 64,070 matched controls who were prescribed at least one anti-hypertensive drug for more than 300 days within 1 year were selected for the nested case-control study. Female C57BL/6 J mice and THP-1 cells stimulated with lipopolysaccharide (LPS) were used for studying systemic responses during sepsis to validate our clinical findings.

Results

The risk of sepsis was lower in current selective beta-blocker users than in non-users (adjusted OR (aOR), 0.842; 95% CI, 0.755-0.939), and in recent users than in non-users (aOR, 0.773; 95% CI, 0.737-0.810). A mean daily dose of ≥0.5 DDD was associated with a lower risk of sepsis (aOR, 0.7; 95% CI, 0.676-0.725). Metoprolol, atenolol, and bisoprolol users had lower risk of sepsis than non-users. In a LPS-induced sepsis mouse model, mice pre-fed with atenolol had significantly reduced mortality. While atenolol had some mild effects on LPS-induced release of inflammatory cytokines in septic mice, it significantly reduced serum soluble PD-L1 levels. Notably, atenolol treatment reversed the negative correlation of sPD-L1 with inflammatory cytokines in septic mice. Moreover, atenolol markedly downregulated the PD-L1 expression on LPS-stimulated THP-1 monocytes/macrophages via targeting ROS-induced NF-κB and STAT3 activation.

Conclusion

Atenolol pretreatment can reduce sepsis mortality in mice, and in vivo and in vitro studies of PD-L1 expression suggest a role for atenolol in the modulation of immune homeostasis. These findings may contribute to the reduced incidence of sepsis in hypertensive patients with premorbid treatment with selective beta-blockers, especially atenolol.

Plants' bioactive secondary metabolites in the management of sepsis: Recent findings on their mechanism of action

Sepsis is a severe inflammatory response to systemic infection and is a threatening cause of death in intensive care units. In recent years, a number of studies have been conducted on the protective effect of natural products against sepsis-induced organ injury. However, a comprehensive review of these studies indicating the mechanisms of action of the bioactive compounds is still lacking. In this context, this review aimed to provide an updated analysis of the mechanism of action of plants' secondary metabolites in the management of sepsis. Scopus, Science Direct, Google Scholar, and PubMed were searched from inception to July 2022. A variety of secondary metabolites were found to be effective in sepsis management including allicin, aloin, cepharanthine, chrysin, curcumin, cyanidin, gallic acid, gingerol, ginsenoside, glycyrrhizin, hesperidin, kaempferol, narciclasine, naringenin, naringin, piperine, quercetin, resveratrol, rosmarinic acid, shogaol, silymarin, sulforaphane, thymoquinone, umbelliferone, and zingerone. The protective effects exerted by these compounds can be ascribed to their antioxidant properties as well as induction of endogenous antioxidant mechanisms, and also via the downregulation of inflammatory response and reduction of biochemical and inflammatory markers of sepsis. These findings suggest that these secondary metabolites could be of potential therapeutic value in the management of sepsis, but human studies must be performed to provide strength to their potential clinical relevance in sepsis-related morbidity and mortality reduction.

Evaluating the effects of curcumin nanomicelles on clinical outcome and cellular immune responses in critically ill sepsis patients: A randomized, double-blind, and placebo-controlled trial

Introduction

In sepsis, the immune system is overreacting to infection, leading to organ dysfunction and death. The purpose of this study was to investigate the impacts of curcumin nanomicelles on clinical outcomes and cellular immune responses in critically ill sepsis patients.

Method

For 10 days, 40 patients in the intensive care units (ICU) were randomized between the nano curcumin (NC) and placebo groups in a randomized study. We evaluated serum levels of biochemical factors, inflammatory biomarkers, the mRNA expression levels of FOXP3, NLRP-3, IFN-γ, and NF-κp genes in the PBMCs, and clinical outcomes before the beginning of the supplementation and on days 5 and 10.

Results

NLR family pyrin domain containing 3 (NLRP3), interferon gamma (IFN-γ), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) mRNA expression levels significantly P = 0.014, P = 0.014, and P = 0.019, respectively) decreased, but forkhead box P3 (FOXP3) mRNA expression levels increased significantly (P = 0.008) in the NC group compared to the placebo group after 10 days. NC supplementation decreased serum levels of IL-22, IL-17, and high mobility group box 1 (HMGB1) (P < 0.05). Nevertheless, biochemical factors and nutritional status did not differ significantly (P > 0.05). NC supplementation resulted in decreased sequential organ failure assessment and multiple organ dysfunction syndromes scores, while it did not have significant impacts on length of stay in the ICU, systolic blood pressure, diastolic blood pressure, a saturation of oxygen (%), and respiratory rate (breaths/min) PaO2/FiO2 (p > 0.05).

Conclusion

For critically ill patients with sepsis, NC supplementation may be an effective therapeutic strategy. More randomized clinical trials involving longer follow-up periods and different doses are needed to achieve the best results.

Prognostic significance of the angiopoietin-2 for early prediction of septic shock in severe sepsis patients

Aim

The current study investigated the plasma levels of angiopoietin-1/-2 and their association with clinical outcomes of sepsis.

Methods

Angiopoietin-1 and -2 levels were quantified in plasma from 105 patients with severe sepsis by ELISA.

Results

Angiopoietin-2 levels elevated according to the severity of sepsis progression. Angiopoietin-2 levels were correlated with mean arterial pressure and platelets counts, total bilirubin, creatinine, procalcitonin, lactate levels and SOFA score. Angiopoietin-2 levels accurately discriminated for sepsis with an AUC = 0.97 and septic shock from severe sepsis patients (AUC = 0.778).

Conclusion

Plasma angiopoietin-2 levels may serve as an additional biomarker for severe sepsis and septic shock.

Stimuli-responsive and biomimetic delivery systems for sepsis and related complications

Sepsis, a consequence of an imbalanced immune response to infection, is currently one of the leading causes of death globally. Despite advances in the discoveries of potential targets and nanotechnology, sepsis still lacks effective drug delivery systems for optimal treatment. Stimuli-responsive and biomimetic nano delivery systems, specifically, are emerging as advanced bio-inspired nanocarriers for enhancing the treatment of sepsis. Herein, we present a critical review of different stimuli-responsive systems, including pH-; enzyme-; ROS- and toxin-responsive nanocarriers, reported in the delivery of therapeutics for sepsis. Biomimetic nanocarriers, utilizing natural pathways in the inflammatory cascade to optimize sepsis therapy, are also reviewed, in addition to smart, multifunctional vehicles. The review highlights the nanomaterials designed for constructing these systems; their physicochemical properties; the mechanisms of drug release; and their potential for enhancing the therapeutic efficacy of their cargo. Current challenges are identified and future avenues for research into the optimization of bio-inspired nano delivery systems for sepsis are also proposed. This review confirms the potential of stimuli-responsive and biomimetic nanocarriers for enhanced therapy against sepsis and related complications.

Steps To Prevent Mortality in a Patient with Coinciding Severe Sepsis and Cardiogenic Shock Post-Non-ST-Elevation Myocardial Infarction (NSTEMI): A Case Report

Severe sepsis is characterized by acute organ dysfunction secondary to an infective source, often requiring emergent medical intervention. The severity of sepsis is determined by a criterion that focuses on the presence of fever, tachycardia, tachypnea, leukocytosis, lactic acidosis, hypotension, evidence of organ failure, and the presence of an infective source. Management of sepsis in patients with a coinciding ischemic event such as a myocardial infarction (MI), is difficult, given the prognosis is poor and there is a high risk for mortality. This case report explores methodical medical measures taken to prevent mortality in an 81-year-old Hispanic male that developed severe sepsis in conjunction with a complicated presentation of a non-ST-elevation myocardial infarction (NSTEMI).

Peptidome profiling for the immunological stratification in sepsis: a proof of concept study

Sepsis has been called the graveyard of pharmaceutical companies due to the numerous failed clinical trials. The lack of tools to monitor the immunological status in sepsis constrains the development of therapies. Here, we evaluated a test based on whole plasma peptidome acquired by MALDI-TOF-mass spectrometer and machine-learning algorithms to discriminate two lipopolysaccharide-(LPS) induced murine models emulating the pro- and anti-inflammatory/immunosuppression environments that can be found during sepsis. The LPS group was inoculated with a single high dose of LPS and the IS group was subjected to increasing doses of LPS, to induce proinflammatory and anti-inflammatory/immunosuppression profiles respectively. The LPS group showed leukopenia and higher levels of cytokines and tissue damage markers, and the IS group showed neutrophilia, lymphopenia and decreased humoral response. Principal component analysis of the plasma peptidomes formed discrete clusters that mostly coincided with the experimental groups. In addition, machine-learning algorithms discriminated the different experimental groups with a sensitivity of 95.7% and specificity of 90.9%. Data reveal the potential of plasma fingerprints analysis by MALDI-TOF-mass spectrometry as a simple, speedy and readily transferrable method for sepsis patient stratification that would contribute to therapeutic decision-making based on their immunological status.

Matrix Metalloproteinases: From Molecular Mechanisms to Physiology, Pathophysiology, and Pharmacology

The first matrix metalloproteinase (MMP) was discovered in 1962 from the tail of a tadpole by its ability to degrade collagen. As their name suggests, matrix metalloproteinases are proteases capable of remodeling the extracellular matrix. More recently, MMPs have been demonstrated to play numerous additional biologic roles in cell signaling, immune regulation, and transcriptional control, all of which are unrelated to the degradation of the extracellular matrix. In this review, we will present milestones and major discoveries of MMP research, including various clinical trials for the use of MMP inhibitors. We will discuss the reasons behind the failures of most MMP inhibitors for the treatment of cancer and inflammatory diseases. There are still misconceptions about the pathophysiological roles of MMPs and the best strategies to inhibit their detrimental functions. This review aims to discuss MMPs in preclinical models and human pathologies. We will discuss new biochemical tools to track their proteolytic activity in vivo and ex vivo, in addition to future pharmacological alternatives to inhibit their detrimental functions in diseases. SIGNIFICANCE STATEMENT: Matrix metalloproteinases (MMPs) have been implicated in most inflammatory, autoimmune, cancers, and pathogen-mediated diseases. Initially overlooked, MMP contributions can be both beneficial and detrimental in disease progression and resolution. Thousands of MMP substrates have been suggested, and a few hundred have been validated. After more than 60 years of MMP research, there remain intriguing enigmas to solve regarding their biological functions in diseases.

Nano-curcumin supplementation in critically ill patients with sepsis: a randomized clinical trial investigating the inflammatory biomarkers, oxidative stress indices, endothelial function, clinical outcomes and nutritional status

Sepsis is a severe reaction and excessive immune response to infection, which can lead to organ dysfunction, and death. This study aimed to investigate the protective effect of nano-curcumin (NC) on inflammatory biomarkers, endothelial function, oxidative stress indices, biochemical factors, nutritional status, and clinical outcomes in patients with sepsis. In the present double-blind placebo-controlled randomized clinical trial, 40 ICU-admitted patients were randomly allocated into either NC or placebo group for 10 days. Both nano-curcumin (160 mg) and placebo were administered via a nasogastric tube twice a day. The mRNA expression of nuclear-related factor 2 (Nrf-2), BCL2 associated X (BAX), B-cell lymphoma 2 (BCL-2), and toll-like receptor 4 (TLR-4) genes in the peripheral blood mononuclear cells (PBMCs), and the serum levels of primary, secondary, tertiary, and exploratory outcomes were assessed before the baseline and on days 5 and 10. There were significant improvements in the primary outcomes, including inflammatory markers (IL-6, IL-18, IL-1β, IL-10, TLR-4, BCL-2 and BAX), markers of endothelial function (ICAM-1 and VCAM-1), and oxidative stress indices (malondialdehyde (MDA), nuclear-related factor 2 (Nrf-2), catalase, superoxide dismutase (SOD), and TAC) (p < 0.005) in the NC group compared to the placebo group after 10 days, while no significant increase was observed in the glutathione peroxidase (GPx) level between the two groups. However, no significant decrease was observed in the levels of secondary outcomes, including biochemical factors (creatinine, fasting blood sugar (FBS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total bilirubin, triglycerides (TG) and total cholesterol (TC)) (P > 0.05). Our results showed that in the tertiary outcome (nutritional status), there was no significant increase (P > 0.05) except for TLC (P = 0.003). NC supplementation also resulted in a significant decrease in the exploratory outcomes including the SOFA score and the duration of mechanical ventilation (P < 0.05). Supplementation with NC may be a promising treatment strategy for critically ill patients with sepsis. However, further experiments are suggested to investigate the effects of nano-curcumin on biochemical pathways involved in sepsis.

Impact of novel microbial secondary metabolites on the pharma industry

Microorganisms are remarkable producers of a wide diversity of natural products that significantly improve human health and well-being. Currently, these natural products comprise half of all the pharmaceuticals on the market. After the discovery of penicillin by Alexander Fleming 85 years ago, the search for and study of antibiotics began to gain relevance as drugs. Since then, antibiotics have played a valuable role in treating infectious diseases and have saved many human lives. New molecules with anticancer, hypocholesterolemic, and immunosuppressive activity have now been introduced to treat other relevant diseases. Smaller biotechnology companies and academic laboratories generate novel antibiotics and other secondary metabolites that big pharmaceutical companies no longer develop. The purpose of this review is to illustrate some of the recent developments and to show the potential that some modern technologies like metagenomics and genome mining offer for the discovery and development of new molecules, with different functions like therapeutic alternatives needed to overcome current severe problems, such as the SARS-CoV-2 pandemic, antibiotic resistance, and other emerging diseases. KEY POINTS: • Novel alternatives for the treatment of infections caused by bacteria, fungi, and viruses. • Second wave of efforts of microbial origin against SARS-CoV-2 and related variants. • Microbial drugs used in clinical practice as hypocholesterolemic agents, immunosuppressants, and anticancer therapy.

MRSA-induced endothelial permeability and acute lung injury are attenuated by FTY720 S-phosphonate

Disruption of the lung endothelial barrier is a hallmark of acute respiratory distress syndrome (ARDS), for which no effective pharmacologic treatments exist. Prior work has demonstrated that FTY720 S-phosphonate (Tys), an analog of sphingosine-1-phosphate (S1P) and FTY720, exhibits potent endothelial cell (EC) barrier protective properties. In this study, we investigated the in vitro and in vivo efficacy of Tys against methicillin-resistant Staphylococcus aureus (MRSA), a frequent bacterial cause of ARDS. Tys-protected human lung EC from barrier disruption induced by heat-killed MRSA (HK-MRSA) or staphylococcal α-toxin and attenuated MRSA-induced cytoskeletal changes associated with barrier disruption, including actin stress fiber formation and loss of peripheral VE-cadherin and cortactin. Tys-inhibited Rho and myosin light chain (MLC) activation after MRSA and blocked MRSA-induced NF-κB activation and release of the proinflammatory cytokines, IL-6 and IL-8. In vivo, intratracheal administration of live MRSA in mice caused significant vascular leakage and leukocyte infiltration into the alveolar space. Pre- or posttreatment with Tys attenuated MRSA-induced lung permeability and levels of alveolar neutrophils. Posttreatment with Tys significantly reduced levels of bronchoalveolar lavage (BAL) VCAM-1 and plasma IL-6 and KC induced by MRSA. Dynamic intravital imaging of mouse lungs demonstrated Tys attenuation of HK-MRSA-induced interstitial edema and neutrophil infiltration into lung tissue. Tys did not directly inhibit MRSA growth or viability in vitro. In conclusion, Tys inhibits lung EC barrier disruption and proinflammatory signaling induced by MRSA in vitro and attenuates acute lung injury induced by MRSA in vivo. These results support the potential utility of Tys as a novel ARDS therapeutic strategy.

Effect of Anti-Inflammatory and Antimicrobial Cosupplementations on Sepsis Prevention in Critically Ill Trauma Patients at High Risk for Sepsis

Background: Sepsis development in patients with trauma is associated with bad prognosis. This study investigated the effect of immunomodulatory interventions in major trauma patients at high risk for sepsis. Methods: In a randomized, double-blinded, controlled design, severe trauma patients were stratified by leukocyte anti-sedimentation rate (LAR) test into high risk (HR) and low risk (LR) for sepsis. The HR patients were randomly allocated into intravenous vitamin C plus vitamin B1 (HR-CB), intramuscular vitamin D plus oral Lactobacillus probiotics (HR-DP), or control (HR-C) groups. The clinical trial was registered at clinicaltrials.gov (https://clinicaltrials.gov/show/NCT04216459). Outcomes: The primary outcome was Acute Physiologic Assessment and Chronic Health Evaluation score II (APACHE II) score. Secondary outcomes included sepsis incidence, changes in Sequential Organ Failure Assessment (SOFA) score, and serum monocyte chemoattractant protein-1 (MCP-1) on day 6 from baseline, 28-day mortality, intensive care unit (ICU), and hospital discharge. Results: The HR-DP, HR-CB, and LR groups showed a significantly lower incidence of sepsis development (20%, 20%, and 16%, respectively, versus 60% in the HR-C group, p-value = 0.004). The three groups also showed a significant improvement in APACHE II and SOFA scores. Besides, MCP-1 levels were significantly decreased in HR-DP and HR-CB groups compared to the HR-C group (p-value ≤ 0.05). Significantly decreased mortality (10% and 16% versus 60% in the HR-C group) and increased ICU discharge (95% and 84% versus 45% in the HR-C group) were observed in HR-CB and LR groups (p-value = 0.001). Conclusion: Both combinations of interventions improved APACHE II scores and reduced sepsis incidence in trauma patients. The LAR combined with injury severity score were good sepsis predictors.

Novel Treatments Targeting the Dysregulated Cell Signaling Pathway during Sepsis

Previously characterized as a purely immune mediated disease, sepsis is now recognized as a dysregulated multisystem response against a pathogen. Recognition of the infectious agent by pathogen recognition receptors (PRRs) can initiate activation of the NF-κB signaling pathway and promote the secretion of proinflammatory cytokines. During sepsis, the activation of NF-κB is dysregulated and results in cytokine storm, or the pathologic release of cytokines. Current treatments for sepsis rely on broad spectrum antimicrobial medications and fluid replacement therapy, to neutralize the inciting pathogen and maintain adequate blood pressure. The addition of vasopressor therapy is also utilized when sepsis progresses to septic shock, which is defined by treatment resistant hypotension. Even though modern treatment guidelines have improved clinical outcomes, the mortality rate of sepsis and septic shock is still 15-20% and 20-50%, respectively. To reduce mortality, recent sepsis treatment research has focused on investigating novel therapeutics that can attenuate the dysregulated NF-κB signaling pathway. Antioxidants, such as Retinoic acid and Oxytocin, can reduce activation of the NF-κB pathway by neutralizing stimulatory reactive oxygen species (ROS). Likewise, anti-inflammatory agents can also affect the NF-κB pathway by decreasing the secretion of proinflammatory cytokines, such as TNFα and IL-6. Novel anti-inflammatory cytokines, such as IL-37 and IL-38, have recently been characterized and shown to reduce inflammation in mice with bacterial sepsis. Separately, antioxidants and anti-inflammatory cytokines show promise as potential therapies for sepsis, however, a combined therapy including both agents may prove more beneficial in further improving clinical outcomes.

The microbial composition of the initial insult can predict the prognosis of experimental sepsis

We hypothesized that the composition of sepsis-inducing bacterial flora influences the course of fecal peritonitis in rodents. Saline or fecal suspensions with a standardized dose range of bacterial colony-forming units (CFUs) were injected intraperitoneally into Sprague–Dawley rats. The qualitative composition of the initial inoculum and the ascites was analyzed separately by MALDI-TOF mass spectrometry. Invasive monitoring was conducted in separate anesthetized groups (n = 12–13/group) after 12, 24, 48 and 72 h to determine rat-specific organ failure assessment (ROFA) scores. Death and ROFA scores peaked at 24 h. At this time, 20% mortality occurred in animals receiving a monomicrobial E. coli suspension, and ROFA scores were significantly higher in the monomicrobial subgroup than in the polymicrobial one (median 6.5; 5.0–7.0 and 5.0; 4.75–5.0, respectively). ROFA scores dropped after 48 h, accompanied by a steady decrease in ascites CFUs and a shift towards intra-abdominal monomicrobial E. coli cultures. Furthermore, we found a relationship between ascites CFUs and the evolving change in ROFA scores throughout the study. Hence, quantitatively identical bacterial loads with mono- or polymicrobial dominance lead to a different degree of sepsis severity and divergent outcomes. Initial and intraperitoneal microbiological testing should be used to improve translational research success.

Sepsis in patients hospitalized with coronavirus disease 2019: how often and how severe?

PURPOSE OF REVIEW

To discuss why severe COVID-19 should be considered sepsis and how co-infection and secondary infection can aggravate this condition and perpetuate organ dysfunction leading to high mortality rates.

RECENT FINDINGS

In severe COVID-19, there is both direct viral toxicity and dysregulated host response to infection. Although both coinfection and/or secondary infection are present, the latest is of greater concern mainly in resource-poor settings. Patients with severe COVID-19 present a phenotype of multiorgan dysfunction that leads to death in an unacceptable high percentage of the patients, with wide variability around the world. Similarly to endemic sepsis, the mortality of COVID-19 critically ill patients is higher in low-income and middle-income countries as compared with high-income countries. Disparities, including hospital strain, resources limitations, higher incidence of healthcare-associated infections (HAI), and staffing issues could in part explain this variability.

SUMMARY

The high mortality rates of critically ill patients with severe COVID-19 disease are not only related to the severity of patient disease but also to modifiable factors, such as the ICU strain, HAI incidence, and organizational aspects. Therefore, HAI prevention and the delivery of best evidence-based care for these patients to avoid additional damage is important. Quality improvement interventions might help in improving outcomes mainly in resource-limited settings.

Parechovirus and enteroviruses among young infants with sepsis in Iran

Background and Objectives

Human parechoviruses (HPeV) and Human enteroviruses (EV) frequently cause a sepsis-like illness in young infants (younger than three months). Therefore, this study was conducted to determine the frequency of HPeV and EV among the young infants with clinical signs and symptoms of sepsis in Ahvaz city, Iran.

Materials and Methods

The blood specimens were collected from 100 (younger than 90 days hospitalized infants) including 54 (56.25%) males and 46 (43.75%) females with clinical signs and symptoms of sepsis-like disease. The RNA was extracted and tested for detection of VP1 region of HPeV and 5 UTR (Untranslated Region) of EV by RT-PCR. The sequences of positive of HPeV were further analyzed to determine HPeV genotyping.

Results

5/100 (5%) of patients including 2/46 (2%) females and 3/54 (3%) males tested positive for HPeV (P=0.85). The analysis of 5 positive VP1 region of HPeV revealed the genotype 1. The analysis of sequencing and phylogenetic tree revealed that the isolated HPeVs were genotype 1. While 38/100 (38%) specimens including 16 (16%) females and 22 (22%) males were tested positive for EV (P=0.68).

Conclusion

The frequency of HPeV genotype 1 was 5% among the young infants with sepsis. While frequency of EV was 38% among the young infants with sepsis. This study showed HPeV genotype 1 and EV are dominant in this region.

Therapeutic Approaches in Modulating the Inflammatory and Immunological Response in Patients With Sepsis, Acute Respiratory Distress Syndrome, and Pancreatitis: An Expert Opinion Review

Immunomodulation has long been an adjunct approach in treating critically ill patients with sepsis, acute respiratory distress syndrome (ARDS), and acute pancreatitis (AP). Hyperactive immune response with immunopathogenesis leads to organ dysfunction and alters the clinical outcomes in critically ill. Though the immune response in the critically ill might have been overlooked, it has gathered greater attention during this novel coronavirus disease 2019 (COVID-19) pandemic. Modulating hyperactive immune response, the cytokine storm, especially with steroids, has shown to improve the outcomes in COVID-19 patients. In this review, we find that immune response pathogenesis in critically ill patients with sepsis, ARDS, and AP is nearly similar. The use of immunomodulators such as steroids, broad-spectrum serine protease inhibitors such as ulinastatin, thymosin alpha, intravenous immunoglobulins, and therapies such as CytoSorb and therapeutic plasma exchange may help in improving the clinical outcomes in these conditions. As the experience of the majority of physicians in using such therapeutics may be limited, we provide our expert comments regarding immunomodulation to optimize outcomes in patients with sepsis/septic shock, ARDS, and AP.

Transcriptome and Literature Mining Highlight the Differential Expression of ERLIN1 in Immune Cells during Sepsis

Sepsis results from the dysregulation of the host immune system. This highly variable disease affects 19 million people globally, and accounts for 5 million deaths annually. In transcriptomic datasets curated from public repositories, we observed a consistent upregulation (3.26-5.29 fold) of ERLIN1-a gene coding for an ER membrane prohibitin and a regulator of inositol 1, 4, 5-trisphosphate receptors and sterol regulatory element-binding proteins-under septic conditions in healthy neutrophils, monocytes, and whole blood. In vitro expression of the ERLIN1 gene and proteins was measured by stimulating the whole blood of healthy volunteers to a combination of lipopolysaccharide and peptidoglycan. Septic stimulation induced a significant increase in ERLIN1 expression; however, ERLIN1 was differentially expressed among the immune blood cell subsets. ERLIN1 was uniquely increased in whole blood neutrophils, and confirmed in the differentiated HL60 cell line. The scarcity of ERLIN1 in sepsis literature indicates a knowledge gap between the functions of ERLIN1, calcium homeostasis, and cholesterol and fatty acid biosynthesis, and sepsis. In combination with experimental data, we bring forth the hypothesis that ERLIN1 is variably modulated among immune cells in response to cellular perturbations, and has implications for ER functions and/or ER membrane protein components during sepsis.

Pattern recognition receptors as therapeutic targets for bacterial, viral and fungal sepsis

Sepsis remains to be a significant health care problem associated with high morbidities and mortalities. Recognizing its heterogeneity, it is critical to understand our host immunological responses to develop appropriate therapeutic approaches according to the type of sepsis. Because pattern recognition receptors are largely responsible for the recognition of microbes, we reviewed their role in immunological responses in the setting of bacterial, fungal and viral sepsis. We also considered their therapeutic potentials in sepsis.

Accuracy of Heparin-Binding Protein in Diagnosing Sepsis: A Systematic Review and Meta-Analysis

OBJECTIVES

Existing studies evaluating the accuracy of heparin-binding protein for the diagnosis of sepsis have been inconsistent. We conducted a systematic review and meta-analysis to assess the totality of current evidence regarding the utility of heparin-binding protein to diagnose sepsis in patients with presumed systemic infection.

DATA SOURCE

PubMed, Embase, the China National Knowledge infrastructure, and WangFang electronic database were searched from inception to December of 2019.

STUDY SELECTION

Two independent reviewers identified eligible studies. Cohort and case-control studies, which measured serum levels of heparin-binding protein among adult patients with suspected sepsis, were eligible for inclusion.

DATA EXTRACTION

Two reviewers independently extracted data elements from the selected studies. A bivariate random-effects meta-analysis model was used to synthesize the prognostic accuracy measures. Risk of bias of studies was assessed with Quality Assessment of Diagnostic Accuracy Studies 2 tool.

DATA SYNTHESIS

We identified 26 studies with 3,868 patients in the meta-analysis. Heparin-binding protein had a pooled sensitivity of 0.85 (95% CI, 0.79-0.90) and a pooled specificity of 0.91 (95% CI, 0.82-0.96) for the diagnosis of sepsis. There was low heterogeneity between the studies (I2 = 12%), and no evidence of publication bias was detected. Heparin-binding protein had a higher sensitivity and specificity when compared with procalcitonin (0.75 [95% CI, 0.62-0.85] and 0.85 [95% CI, 0.73-0.92]) as well as C-reactive protein (0.75 [95% CI, 0.65-0.84] and 0.71 [95% CI, 0.63-0.77]). Serial measurements of heparin-binding protein also showed that heparin-binding protein levels rose significantly at least 24 hours before a diagnosis of sepsis.

CONCLUSIONS

The diagnostic ability of heparin-binding protein is favorable, demonstrating both high sensitivity and specificity in predicting progression to sepsis in critically ill patients. Future studies could assess the incremental value that heparin-binding protein may add to a multimodal sepsis identification and prognostication algorithm for critically ill patients.

Pharmacological Modulation of BET Family in Sepsis

The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis 3.0) recommended defining sepsis as a life-threatening organ dysfunction caused by the host's uncontrolled response to infection. The bromodomain and extra-terminal (BET) protein family (such as BRD2, BRD3, and BRD4), an epigenetic regulator of gene transcription, has recently been recognized as a significant septic regulator of inflammation and immune response, including cytokine and chemokine production. Mechanistically, the two N-terminal conserved tandem bromodomains (namely the first bromodomain [BD1] and the second bromodomain [BD2]) favor the binding of BETs to acetylated histones or transcription factors, thereby initiating gene transcription machinery after CycT1 and CDK9 (also known as P-TEFb) are recruited to gene promoters to phosphorylate RNA pol II. Notably, BD1 and BD2 are not functionally redundant because they have different target genes in innate immune cells. Small-molecule BET inhibitors (BETis) for different BDs, such as I-BET, JQ1, I-BET151, apabetalone, RVX-297, and dBET1 have shown promising therapeutic effects in experimental sepsis models. This mini-review summarizes the emerging roles of BETs and the applications of BETis in sepsis, discusses the existing shortcomings of BETis, and introduces possible future research directions in this area.

Novel insights into the treatment of SARS-CoV-2 infection: An overview of current clinical trials

The emergence of the global pandemic caused by the novel SARS-CoV-2 virus has motivated scientists to find a definitive treatment or a vaccine against it in the shortest possible time. Current efforts towards this goal remain fruitless without a full understanding of the behavior of the virus and its adaptor proteins. This review provides an overview of the biological properties, functional mechanisms, and molecular components of SARS-CoV-2, along with investigational therapeutic and preventive approaches for this virus. Since the proteolytic cleavage of the S protein is critical for virus penetration into cells, a set of drugs, such as chloroquine, hydroxychloroquine, camostat mesylate have been tested in clinical trials to suppress this event. In addition to angiotensin-converting enzyme 2, the role of CD147 in the viral entrance has also been proposed. Mepolizumab has shown to be effective in blocking the virus's cellular entrance. Antiviral drugs, such as remdesivir, ritonavir, oseltamivir, darunavir, lopinavir, zanamivir, peramivir, and oseltamivir, have also been tested as treatments for COVID-19. Regarding preventive vaccines, the whole virus, vectors, nucleic acids, and structural subunits have been suggested for vaccine development. Mesenchymal stem cells and natural killer cells could also be used against SARS-CoV-2. All the above-mentioned strategies, as well as the role of nanomedicine for the diagnosis and treatment of SARS-CoV-2 infection, have been discussed in this review.

Mortality related to drug-resistant organisms in surgical sepsis-3: an 8-year time trend study using sequential organ failure assessment scores

The difference in sequential organ failure assessment (SOFA) scores from the baseline to sepsis is a known predictor of sepsis-3 outcome, but the prognostic value of drug-resistant organisms for mortality is unexplained. We employed sepsis stewardship and herein report an observational study. Study subjects were patients admitted to the Departments of Surgery/Chest Surgery from 2011 through 2018 with a diagnosis of sepsis and a SOFA score of 2 or more. Our sepsis stewardship methods included antimicrobial and diagnostic stewardship and infection control. We determined the primary endpoint as in-hospital death and the secondary endpoint as the annual trend of the risk-adjusted mortality ratio (RAMR). For mortality, we performed logistic regression analysis based on SOFA score, age, sex, comorbid disease, and the presence of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase inhibitor–producing bacteria. In a total of 457 patients, two factors were significant predictors for fatality, i.e., SOFA score of 9 or more with an odds ratio (OR) 4.921 and 95% confidence interval [95% CI] 1.968–12.302 (P = 0.001) and presence of MRSA with an OR 1.83 and 95% CI 1.003–3.338 (P = 0.049). RAMR showed a decrease during the study years (P < 0.05). Early detection of MRSA may help patients survive surgical sepsis-3. Thus, MRSA-oriented diagnosis may play a role in expediting treatment with anti-MRSA antimicrobials.

Immature platelet indices alongside procalcitonin for sensitive and specific identification of bacteremia in the intensive care unit

Hematological markers that can be rapidly analyzed and regularly monitored during a patient's stay on ICU, and that can identify bacterial causes of sepsis are being extensively sought. The significance of platelets in early immunological responses provides justification for assessing their usefulness in the identification of bacteremia amongst sepsis patients. In this preliminary study, the full blood count, including the platelet count by impedance (PLT-I), Immature Platelet Fraction (IPF%) and absolute immature platelet count (AIPC), were analyzed in eighty-two sepsis patients daily over the first 5 days stay on ICU. C-Reactive Protein (CRP), procalcitonin (PCT), and lactate were also analyzed daily. Blood cultures confirmed or excluded the presence of bacteremia. PCT provided the earliest indicator of bacteremia, with significant differences between the two cohorts on day 1. The change in IPF% and AIPC from day 1 to day 2 (Δ IPF% and Δ AIPC) provided the most accurate indication; A combination of Δ IPF% and day 2 PCT, provided a positive predictive value and negative predictive value of 100% and 96.10%, respectively. These data provide strong justification for larger multi-center validation studies to confirm the usefulness of these platelet indices during the assessment of sepsis on the ICU.