# Clinical impact of BioFire Blood Culture Identification 2 implementation in patients with Staphylococcus bacteremia

## TL;DR

This study shows that using the BioFire Blood Culture Identification 2 test helps reduce vancomycin use and improve treatment for certain blood infections.

## Contribution

The study demonstrates that BCID2 implementation significantly reduces vancomycin duration and improves antimicrobial stewardship in MSSA/SOSA bacteremia.

## Key findings

- Vancomycin duration decreased from 1.3 to 0.3 days post-BCID2 implementation.
- Pharmacist interventions increased from 7.1% to 16.3% after BCID2 implementation.
- MSSA bloodstream infection duration was shorter post-BCID2 (2.4 vs. 3.1 days).

## Abstract

The BioFire Blood Culture Identification 2 (BCID2) PCR panel allows for rapid identification of blood pathogens, including Staphylococci other than Staphylococcus aureus (SOSA) and methicillin-susceptible S. aureus (MSSA). The objective of this study was to evaluate how BCID2 implementation impacted duration of vancomycin therapy, clinical outcomes, and rate of pharmacist intervention. This was a multi-center, retrospective study of adult patients admitted with MSSA or SOSA-positive blood cultures. The primary endpoint, days of vancomycin therapy, was compared between the pre- and post-BCID2 periods. Secondary endpoints included duration of MSSA bacteremia, hospital mortality, and pharmacist interventions. Of the 617 patients included in the primary analysis, MSSA bloodstream infection (BSI) accounted for 37.0% (110/297) and 31.6% (101/320) of the pre- and post-BCID2 group, respectively (P = 0.178). The median duration of vancomycin was 1.3 and 0.3 days in the pre- and post-BCID2 groups, respectively (absolute difference, 1.0 days; P < 0.001). The duration of MSSA BSI was 3.1 and 2.4 days in the pre- and post-BCID2 group, respectively (absolute difference, 0.7 days; P = 0.096). Hospital mortality was not different between periods (7.1% [21/297] vs 10.6% [34/320], P = 0.16). Pharmacists successfully intervened to reduce vancomycin duration in 7.1% (21/297) and 16.3% (52/320) of patients in the pre- and post-BCID2 group, respectively (P < 0.001). BCID2 implementation shortened the duration of vancomycin in patients with MSSA or SOSA bacteremia. These data support BCID2 as a critical tool to improve appropriate antibiotic selection and shorten the time to safer and more effective treatment for patients with SOSA and MSSA bacteremia.

PCR-based blood culture testing with concurrent antimicrobial stewardship program review continues to facilitate the initiation of pathogen-targeted antimicrobials in a shorter amount of time compared to traditional methods. The initiation of pathogen-targeted antimicrobials compared to non-pathogen-targeted antimicrobials has been shown to improve clinical outcomes in bloodstream infections caused by specific pathogens (e.g., methicillin-susceptible Staphylococcus aureus [MSSA]). Additionally, the adverse effects of vancomycin may be decreased with a shorter duration in blood culture contamination caused by coagulase-negative Staphylococcus species. This retrospective study evaluated the amount of time BCID2 results with pharmacist review and intervention reduced time to pathogen-targeted antimicrobials in MSSA, and time to discontinuation in blood culture contamination by coagulase-negative Staphylococcus species. Secondary outcomes mainly evaluated the clinical effects of these interventions.