Daily Sepsis Research Analysis
Policy-level decolonisation strategy shifts in ICUs, rapid antibiotic susceptibility testing directly from positive blood cultures, and nurse staffing effects on hospital-onset MRSA bloodstream infections emerged as key themes. Together, these studies inform antimicrobial stewardship, diagnostic acceleration for bloodstream infections, and hospital infection prevention.
Summary
Policy-level decolonisation strategy shifts in ICUs, rapid antibiotic susceptibility testing directly from positive blood cultures, and nurse staffing effects on hospital-onset MRSA bloodstream infections emerged as key themes. Together, these studies inform antimicrobial stewardship, diagnostic acceleration for bloodstream infections, and hospital infection prevention.
Research Themes
- ICU decolonisation strategies and resistance selection
- Rapid antimicrobial susceptibility testing from positive blood cultures
- Nurse staffing and prevention of hospital-onset MRSA bloodstream infections
Selected Articles
1. Universal versus targeted chlorhexidine and mupirocin decolonisation and clinical and molecular epidemiology of Staphylococcus epidermidis bloodstream infections in patients in intensive care in Scotland, UK: a controlled time-series and longitudinal genotypic study.
In two Scottish ICUs, de-escalating from universal to targeted decolonisation reduced MRSE bloodstream infections and the probability that SE-BSI were MRSE, without increasing overall BSI. Chlorhexidine exposure correlated with MRSE-BSI incidence, and genotyping showed fewer multidrug-resistant sequence types after de-escalation.
Impact: This quasi-experimental, genomics-informed study challenges the assumption that universal decolonisation is uniformly beneficial and links chlorhexidine pressure to MRSE selection, informing ICU infection prevention policies.
Clinical Implications: ICUs with low MRSA prevalence should consider targeted rather than universal decolonisation and monitor for MRSE selection under chlorhexidine use, balancing device-associated infection risks and resistance ecology.
Key Findings
- MRSE-BSI incidence declined from 10.4 to 4.3 per 1000 occupied bed days after de-escalation at the intervention ICU.
- The percentage probability that SE-BSI were MRSE decreased from 89.2% to 56.7% post-de-escalation.
- MRSE-BSI incidence density was positively associated with chlorhexidine use, but not mupirocin use.
- Genotyping and WGS indicated fewer multidrug-resistant sequence types and resistance/biofilm genes after de-escalation.
Methodological Strengths
- Before-after-control-impact time-series design across two ICUs
- Integrated antimicrobial susceptibility, MLST, and whole-genome sequencing over a 12+ year period
Limitations
- Retrospective, non-randomised design susceptible to secular trends and unmeasured confounding
- Findings from two ICUs in low-MRSA settings may limit generalisability
Future Directions: Prospective multicentre evaluations of decolonisation strategies stratified by local MRSA prevalence, coupled with resistome surveillance and device-associated infection outcomes.
2. Registered nurse workload and hospital-onset methicillin-resistant Staphylococcus aureus bloodstream infections.
Using national administrative datasets, each additional RN hour per patient day correlated with a 3% reduction in hospital-onset MRSA bloodstream infection rates. These findings underscore the infection prevention value of adequate nurse staffing.
Impact: Quantifies a direct association between nurse staffing and a key bloodstream infection outcome, informing staffing policies and infection prevention planning.
Clinical Implications: Hospitals should consider nurse staffing levels as a modifiable lever to reduce hospital-onset MRSA BSI, integrating staffing metrics into infection control programs.
Key Findings
- Each additional RN hour per patient day was associated with a 3% decrease in hospital-onset MRSA bloodstream infection rate.
- Analysis leveraged data from the American Hospital Association Survey and Centers for Medicare & Medicaid Services.
Methodological Strengths
- Use of large national datasets across hospitals
- Clear, interpretable effect size per RN hour per patient day
Limitations
- Observational design cannot establish causality and may be confounded by hospital case mix and resources
- Limited methodological details in the abstract; lack of patient-level covariates described
Future Directions: Prospective evaluations of staffing interventions and cost-effectiveness analyses to guide policy; explore effects on other HAIs.
3. Evaluation of EUCAST rapid antibiotic susceptibility testing for positive blood cultures in the Autobio BC60 blood culture system.
In 234 spiked positive blood culture samples, EUCAST RAST on the Autobio BC system achieved high categorical agreement (≈99–100%) with standard disk diffusion at 4–20 hours, with 0% major errors and 1.3% very major errors across time points. This supports earlier AST reporting directly from positive bottles.
Impact: Validates rapid AST directly from positive blood cultures on a widely used system with excellent agreement metrics, enabling faster targeted therapy for bloodstream infections.
Clinical Implications: Laboratories using Autobio BC can implement EUCAST RAST with QC to provide reliable AST results within hours of positivity, expediting de-escalation/escalation in sepsis management.
Key Findings
- High categorical agreement for RAST vs sDD at 4, 8, and 20 hours across six species (≈98.7–100%).
- Very major errors were 1.3% and major errors 0% at all time points; minor errors ≤1.4%.
- Feasibility of performing EUCAST RAST directly on positive Autobio BC bottles with reliable outcomes.
Methodological Strengths
- Standardised head-to-head comparison with sDD across multiple time points
- Coverage of key Gram-negative and Gram-positive pathogens with species-specific metrics
Limitations
- Spiked samples rather than consecutive clinical isolates; lacks patient outcome correlation
- Single blood culture platform; external validity to other systems not assessed
Future Directions: Prospective clinical validation linking RAST-guided therapy to time-to-effective therapy and patient outcomes; assess performance across different blood culture systems.