Impact of rapid identification of Staphylococcus aureus bloodstream infection without antimicrobial stewardship intervention on antibiotic optimization and clinical outcomes

Optimizing antibiotic use in MSSA bacteremia: a stewardship-focused approach

Antimicrobial stewardship is essential for optimizing therapy in bloodstream infections. Methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia requires prompt beta-lactam treatment, and delays in transitioning from empirical anti-MRSA therapy can result in adverse outcomes. Rapid diagnostics like the BioFire Blood Culture Identification (BCID) PCR panel, combined with stewardship interventions, significantly improve care by reducing unnecessary broad-spectrum antimicrobial use. A study by Yetukuri et al. demonstrated that integrating BCID with stewardship efforts reduced time to optimal therapy by 20 h (49 vs 29.1 h, P < 0.001) and shortened both bacteremia duration and anti-MRSA therapy without affecting mortality or hospital stay. These findings emphasize that stewardship programs, including real-time reviews and prescriptive guidance, are critical for translating rapid diagnostic results into timely, targeted treatment. Leveraging stewardship with advanced diagnostics offers a strategic approach to enhancing outcomes and combating antimicrobial resistance.

Impact of rapid blood culture identification PCR panel on optimal antibiotic use in methicillin-susceptible Staphylococcus aureus bacteremia

Rapid identification of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia may optimize antibiotic use and clinical outcomes. The study objective was to assess the impact of the BioFire® blood culture identification (BCID) polymerase chain reaction (PCR) panel on antibiotic use and clinical outcomes in patients with MSSA bacteremia. This was a retrospective chart review of adult inpatients with MSSA bacteremia during the pre-PCR (June 2018-December 2019) and post-PCR (June 2020-December 2021) implementation periods. The primary endpoint was the difference between the pre-PCR and post-PCR groups in time to optimal MSSA antibiotic therapy (oxacillin or cefazolin). Secondary endpoints included duration of anti-MRSA antibiotic use, in-hospital mortality, hospital and ICU lengths of stay, duration of bacteremia, and 30-day MSSA-related and all-cause readmissions. Two hundred patients were included in the study (100 per group). Median time to optimal therapy was reduced by 19.9 hours in the post-PCR group (49 vs 29.1 hours, respectively, P < 0.001). PCR implementation was associated with significant reductions in the initiation of empiric anti-MRSA antibiotic therapy (98% vs 84%, P = 0.001), duration of empiric anti-MRSA antibiotic use (44.2 vs 20.9 hours, P < 0.001), and duration of bacteremia (68.6 vs 47.3 hours, P = 0.015). No significant differences in length of stay, in-hospital mortality, or 30-day MSSA-related or all-cause readmissions were observed. In patients with MSSA bacteremia, BCID PCR panel implementation decreased time to optimal MSSA antibiotic therapy, duration of bacteremia, and duration of empiric anti-MRSA antibiotic therapy.

IMPORTANCE

In this retrospective study of 200 patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, the implementation of the BioFire® blood culture identification polymerase chain reaction (PCR) panel was associated with a decreased time to optimal MSSA antibiotic therapy and shorter durations of empiric anti-MRSA antibiotic therapy and bacteremia. The findings demonstrate the significant role of rapid PCR testing and routine stewardship review in optimizing antimicrobial therapy and management of MSSA bacteremia.

Rapid Diagnostic Tests and Antimicrobial Stewardship Programs for the Management of Bloodstream Infection: What Is Their Relative Contribution to Improving Clinical Outcomes? A Systematic Review and Network Meta-analysis

BACKGROUND

Evidence about the clinical impact of rapid diagnostic tests (RDTs) for the diagnosis of bloodstream infections is limited, and whether RDT are superior to conventional blood cultures (BCs) embedded within antimicrobial stewardship programs (ASPs) is unknown.

METHODS

We performed network meta-analyses using results from studies of patients with bloodstream infection with the aim of comparing the clinical impact of RDT (applied on positive BC broth or whole blood) to conventional BC, both assessed with and without ASP with respect to mortality, length of stay (LOS), and time to optimal therapy.

RESULTS

Eighty-eight papers were selected, including 25 682 patient encounters. There was an appreciable amount of statistical heterogeneity within each meta-analysis. The network meta-analyses showed a significant reduction in mortality associated with the use of RDT + ASP versus BC alone (odds ratio [OR], 0.72; 95% confidence interval [CI], .59-.87) and with the use of RDT + ASP versus BC + ASP (OR, 0.78; 95% CI, .63-.96). No benefit in survival was found associated with the use of RDT alone nor with BC + ASP compared to BC alone. A reduction in LOS was associated with RDT + ASP versus BC alone (OR, 0.91; 95% CI, .84-.98) whereas no difference in LOS was shown between any other groups. A reduced time to optimal therapy was shown when RDT + ASP was compared to BC alone (-29 hours; 95% CI, -35 to -23), BC + ASP (-18 hours; 95% CI, -27 to -10), and to RDT alone (-12 hours; 95% CI, -20 to -3).

CONCLUSIONS

The use of RDT + ASP may lead to a survival benefit even when introduced in settings already adopting effective ASP in association with conventional BC.

Clinical Impact of Accelerate PhenoTM Rapid Blood Culture Detection System in Bacteremic Patients

BACKGROUND

Accelerate Pheno blood culture detection system (AXDX) provides identification (ID) and antimicrobial susceptibility testing (AST) results within 8h of blood culture growth. Limited data exists regarding its clinical impact. Other rapid platforms coupled with antimicrobial stewardship program (ASP) real-time notification (RTN) have shown improved length of stay (LOS) in bacteremia.

METHODS

A single-center, quasi-experimental study of adult bacteremic inpatients before/after AXDX implementation was conducted comparing clinical outcomes from 1 historical and 2 intervention cohorts (AXDX and AXDX+RTN). Primary outcome was LOS.

RESULTS

Of 830 bacteremic episodes, 188 (77%) of 245 historical and 308 (155 AXDX, 153 AXDX+RTN; 65%) of 585 intervention episodes were included. Median LOS was shorter with AXDX (6.3d) and AXDX+RTN (6.7d) compared to historical (8.1d; P=0.001). Achievement of optimal therapy (AOT) was more frequent (93.6% and 95.4%) and median time to optimal therapy (TTOT) was faster (1.3d and 1.4d) in AXDX and AXDX+RTN compared to historical (84.6%, P≤0.001 and 2.4d; P≤0.001) respectively. Median antimicrobial days of therapy (DOT) was shorter in both intervention arms compared to historical (6d each vs 7d; P=0.011). Median LOS benefit was most pronounced in patients with coagulase negative Staphylococcus bacteremia (5.5d and 4.5d vs 7.2d; P=0.003) in AXDX, AXDX+RTN, and historical cohorts respectively.

CONCLUSIONS

LOS, AOT, TTOT, and total DOT significantly improved after AXDX implementation. Addition of RTN did not show further improvement over AXDX and an already active ASP. These results suggest AXDX can be integrated into healthcare systems with an active ASP even without the resources to include RTN.

Implementation of Rapid Diagnostic Testing without Active Stewardship Team Notification for Gram-Positive Blood Cultures in a Community Teaching Hospital

In community hospitals, antimicrobial stewardship team notification of rapid diagnostic testing (RDT) results may not be feasible. A retrospective quasi-experimental study was conducted evaluating 252 adult inpatients with blood cultures positive for Gram-positive cocci in clusters (pre-RDT, n = 143; post-RDT, n = 109). The median time to appropriate therapy was significantly shorter in the post-RDT group (15 versus 0 h, P < 0.001), and the mean length of stay for patients with coagulase-negative staphylococcus was significantly shorter (10.5 versus 7.7 days; P = 0.015).

New paradigm for rapid achievement of appropriate therapy in special populations: coupling antibiotic dose optimization rapid microbiological methods

INTRODUCTION

Some special patient populations (e.g. critically ill, burns, hematological malignancy, post-major surgery, post-major trauma) have characteristics that lead to higher rates of failure and mortality associated with infection. Choice of effective antibiotics and optimized doses are challenging in these patients that are commonly infected by multidrug-resistant pathogens. Areas covered: A review of the importance of diagnosis and the place of newer microbiological methods (e.g. whole-genome sequencing) to ensure rapid transition from empiric to directed antibiotic therapy is provided. The effects of pathophysiological changes on antibiotic pharmacokinetics are also provided. Expert opinion: Product information dosing regimens do not address the pharmacokinetic alterations that can occur in special patient populations and increase the likelihood of therapeutic failure and the emergence of bacterial resistance. Altered dosing approaches, supplemented with the use of dosing software and therapeutic drug monitoring, may be needed to ensure optimal antibiotic exposure and better therapeutic outcomes in these patients with severe infection. Dose optimization needs to be coupled with advanced microbiological techniques that enable rapid microbiological identification and characterization of resistance mechanism to ensure that maximally effective directed therapy can be chosen.