Impact of antimicrobial stewardship with the Xpert MRSA/SA BC assay at a tertiary hospital in Japan

J Infect Chemother. 2023 Jul;29(7):693-699. doi: 10.1016/j.jiac.2023.03.021. Epub 2023 Apr 6.

Abstract

Introduction: Genetic testing is gaining increasing importance as a part of antimicrobial stewardship (AS). Rapid identification and determination of methicillin susceptibility using the Xpert MRSA/SA BC assay can improve the management of Staphylococcus aureus bacteremia (SAB) and reduce inappropriate antibiotic use. However, few reports have described the effectiveness of this approach.

Methods: The present study aimed to assess the influence of AS using the Xpert MRSA/SA BC assay. Cases were classified into the pre-intervention group (n = 98 patients), in which SAB was identified by traditional culture (November 2017 to November 2019), and the post-intervention group (n = 97 patients), in which the Xpert MRSA/SA BC assay was performed when necessary (December 2019 to December 2021).

Results: Patient characteristics, prognosis, duration of antimicrobial use, and length of hospital stay were compared between the groups. The Xpert assay was performed in 66 patients in the post-intervention group (68.0%). The two groups showed no significant differences in severity and mortality. The rate of cases treated with anti-MRSA agents reduced following the intervention (65.3% vs. 40.4%, p = 0.008). The number of cases involving definitive therapy within 24 h was higher in the post-intervention group (9.2% vs. 24.7%, p = 0.007). The hospitalization rate at >60 days was lower in Xpert implementation cases among MRSA bacteremia cases (28.6% vs. 0%, p = 0.01).

Conclusions: Thus, the Xpert MRSA/SA BC assay has potential as an AS tool, especially for early definitive treatment to SAB and reduction of long-term hospitalization in MRSA bacteremia cases.

Keywords: Antimicrobial stewardship; Staphylococcus bacteremia; Xpert MRSA/SA BC assay.

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Antimicrobial Stewardship*
  • Bacteremia* / diagnosis
  • Bacteremia* / drug therapy
  • Humans
  • Japan
  • Methicillin-Resistant Staphylococcus aureus* / genetics
  • Staphylococcal Infections* / diagnosis
  • Staphylococcal Infections* / drug therapy
  • Tertiary Care Centers

Substances

  • Anti-Bacterial Agents