Daily Sepsis Research Analysis
Analyzed 41 papers and selected 3 impactful papers.
Summary
Three impactful studies advanced sepsis care across therapy, biomarkers, and systems biology. A meta-analysis discourages ceftriaxone for MSSA bacteremia due to higher 30-day mortality, human mechanistic data implicate annexin A2 proteolysis in sepsis-related microvasculopathy, and extracellular vesicle RNA profiling reveals pathogen-specific immune signatures that mirror organ-level transcriptomes.
Research Themes
- Antimicrobial stewardship and outcomes in bloodstream infections/sepsis
- Endothelial/microvascular pathobiology and novel biomarkers in sepsis
- Extracellular vesicle transcriptomics for pathogen-specific host-response profiling
Selected Articles
1. Ceftriaxone for methicillin-susceptible
Across 11 comparative studies (n=2,568), ceftriaxone use for MSSA bacteremia was associated with higher 30-day mortality (OR 3.33, 95% CI 2.17–5.10) versus ASPs/cefazolin, with no significant difference at 90 days. Clinical success and microbiologic clearance were similar, and adverse events did not differ, arguing against routine ceftriaxone use, particularly as initial therapy.
Impact: Provides the strongest current comparative evidence indicating harm with ceftriaxone for MSSA bacteremia, directly informing antibiotic selection and stewardship.
Clinical Implications: For MSSA bloodstream infections, prioritize antistaphylococcal penicillins or cefazolin over ceftriaxone, especially in severe illness or potential sepsis. Reserve ceftriaxone only when compelling logistical constraints exist and promptly de-escalate when feasible.
Key Findings
- Eleven studies (n=2,568) compared ceftriaxone to ASPs/cefazolin for MSSA bacteremia.
- Ceftriaxone increased 30-day mortality (OR 3.33; 95% CI 2.17–5.10).
- No significant difference in 90-day mortality, clinical success, or microbiologic clearance.
- Adverse event rates were similar between groups.
Methodological Strengths
- Prospective protocol registration (PROSPERO CRD42024595748) and multi-database search.
- Random-effects meta-analysis with predefined primary outcomes (30- and 90-day mortality).
Limitations
- Included studies were observational and subject to confounding by indication.
- Heterogeneity in dosing, source control, and illness severity; lack of randomized trials.
Future Directions: Well-designed randomized controlled trials comparing ceftriaxone to ASPs/cefazolin in MSSA bacteremia, stratified by source, inoculum, and severity, are needed to resolve residual uncertainty.
BACKGROUND: Bloodstream infections (BSIs) by methicillin-susceptible Staphylococcus aureus (MSSA) are a significant cause of morbidity and mortality, traditionally treated with antistaphylococcal penicillins (ASPs) or cefazolin. Ceftriaxone has emerged as an alternative due to its once-daily dosing regimen and favourable safety profile; however, its efficacy compared to the standard of care (SoC) remains controversial. This evidence synthesis aimed to assess the role of ceftriaxone in treating MSSA-BSIs. METHODS: A systematic literature search was conducted in PubMed, Emba
2. Sepsis-triggered proteolysis of profibrinolytic annexin A2 associated with microvasculopathy-related organ dysfunction.
In a human case-control study (n=92), sepsis was associated with reduced annexin A2 integrity and diminished cell-surface plasmin generation, driven by serine protease-mediated proteolysis. Annexin A2 loss correlated with IL-18 levels and dysfunction across renal, pulmonary, cardiovascular, and neurologic systems, positioning A2 proteolysis as a candidate biomarker and therapeutic target for sepsis microvasculopathy.
Impact: Links a specific fibrinolytic pathway protein to human sepsis organ dysfunction with mechanistic assays, advancing endothelial pathobiology and biomarker discovery.
Clinical Implications: Annexin A2 integrity and plasmin-generating capacity may serve as biomarkers of sepsis-related microvascular dysfunction; targeting the responsible serine protease or stabilizing A2 could be explored therapeutically.
Key Findings
- Sepsis patients showed significantly reduced annexin A2 integrity and decreased cell-surface plasmin generation.
- Membrane-associated serine protease activity mediated annexin A2 proteolysis during sepsis.
- Annexin A2 reduction correlated with IL-18 and with renal, pulmonary, cardiovascular, and neurologic dysfunction.
Methodological Strengths
- Human case-control design with both cellular (PBMC) and plasma assessments.
- Convergent mechanistic assays (immunoblot, fluorometry) linking protein integrity to functional plasmin generation.
Limitations
- Observational design limits causal inference and temporal dynamics.
- Serine protease identity and upstream triggers were not fully delineated; modest sample size.
Future Directions: Longitudinal studies to map annexin A2 dynamics, protease identification, and interventional trials testing A2 stabilization or protease inhibition to prevent microvasculopathy.
Sepsis is a systemic inflammatory disorder marked by dysregulated inflammation and coagulopathy. Annexin A2 (A2), a profibrinolytic protein, assembles plasminogen and tissue plasminogen activator on cell surfaces, thereby maintaining vascular patency. However, its role in human sepsis has remained poorly defined. We investigated whether A2 undergoes qualitative or quantitative modification during human sepsis with associated end-organ dysfunction. Peripheral blood mononuclear cells and plasma were collected from 65 patients with sepsis and 27 healthy controls. A2 expression and integrity were evaluated with cell surface plasmin generation using immunoblot and fluorometric assays. Both A2 integrity and plasmin generation were significantly reduced in patients with sepsis and with septic shock. A2 underwent sepsis-related membrane-associated proteolysis mediated by a serine protease. A2 reduction correlated with interleukin-18 levels and was significantly associated with renal, pulmonary, cardiovascular, and neurologic dysfunction. A2 proteolysis may represent a novel biomarker and therapeutic target for sepsis-related microvasculopathy.
3. RNA profiles in extracellular vesicles from severe sepsis and meningitis patients reveal pathogen-specific immune signatures in meningococcal versus pneumococcal infections.
Plasma EV-RNA profiling across meningococcal septic shock, meningococcal meningitis, pneumococcal disease, and controls identified 14,909 RNAs and pathogen-specific signatures. Meningococcal septic shock showed strong activation of inflammatory/immune pathways, whereas pneumococcal infection exhibited broad pathway inhibition; EV-RNA patterns mirrored prior postmortem organ transcriptomes in lethal meningococcal shock.
Impact: Introduces a liquid-biopsy EV-RNA framework that discriminates pathogen-specific immune responses in severe infection and aligns with tissue-level programs, offering a translational bridge for diagnostics and precision immunomodulation.
Clinical Implications: EV-RNA signatures may provide minimally invasive diagnostics to distinguish meningococcal versus pneumococcal disease severity and guide targeted adjunctive therapies; elevations of S100A8/A9 and calprotectin support their biomarker potential.
Key Findings
- Detected 14,909 EV-RNAs with distinct pathogen- and syndrome-specific signatures.
- Meningococcal septic shock showed strong activation of inflammatory/immune pathways; pneumococcal disease showed broad pathway inhibition.
- EV-RNA patterns in meningococcal septic shock mirrored postmortem organ transcriptomes from lethal cases.
- S100A12, S100A8/A9, AQP9, and plasma calprotectin were consistently elevated across patient groups.
Methodological Strengths
- Multi-group human comparison with healthy controls using standardized EV isolation and microarray.
- Integrative pathway analysis and cross-validation with independent postmortem tissue transcriptomes.
Limitations
- Sample sizes per group not specified in the abstract; cross-sectional design limits causal inference.
- Microarray-based profiling may lack the depth of RNA-seq; potential confounding by timing of sampling and treatments.
Future Directions: Prospective validation with RNA-seq, explicit sample-size reporting, and development of clinically deployable EV-RNA panels to stratify patients and tailor adjunctive immunotherapies.
BACKGROUND: This study investigates host-pathogen interactions by comparing RNA profiles in plasma extracellular vesicles (EVs) from patients with severe sepsis or meningitis caused by METHODS: Plasma samples from patients with meningococcal septic shock, meningococcal meningitis, pneumococcal infection, and healthy controls were analyzed. EVs were isolated by size exclusion chromatography, and EV derived RNA isolated by ExoRNeasy for examination by microarray. Ingenuity Pathway Analysis searched for pathogen specific EV-RNA signatures and predicted effects on biofunctions and canonical pathways. Additionally, the plasma EV-RNA profiles from the meningococcal sepsis patients were compared with previously published transcriptomic data from post-mortem organ tissue from patients who died from RESULTS: Transcriptomic profiling detected 14,909 EV-RNAs, enriched for small RNAs and canonical markers, and distinct molecular signatures across the disease groups. Patients with meningococcal septic shock displayed the most pronounced transcriptomic dysregulation, followed by milder changes in meningococcal meningitis, whereas pneumococcal disease exhibited broad pathway inhibition. S100A12, S100A8/A9 and AQP9 and plasma calprotectin were consistently elevated in all patient groups. Pathway analysis demonstrated strong activation of inflammatory and immune signaling in meningococcal septic shock, weaker activation in meningitis, and inhibition of multiple pathways in pneumococcal infection. Importantly, EV-RNA plasma profiles from meningococcal septic shock patients closely mirrored transcriptomic patterns in postmortem organ tissues detected in a previous study of lethal meningococcal shock patients. CONCLUSIONS: This study is the first to identify specific EV-RNA profiles in plasma from patients infected with