Combination of ertapenem and penicillin M or cefazolin in the treatment of methicillin-susceptible Staphylococcus aureus bacteremia: multicenter case series.

BACKGROUND

Dual therapy (DT) combining penicillin M or cefazolin with ertapenem has been proposed as treatment of complicated Staphylococcus aureus bacteremia (SAB). We aimed to outline the relevant clinical characteristics and outcomes in real-life practice.

METHODS

We conducted a multicenter retrospective study involving SAB cases treated with DT in five French university hospitals between January 2022 and December 2024.

RESULTS

Thirty-five patients were included, all of them presenting with complicated SAB. Although DT was prescribed for persistent bacteremia, only 21 patients (60%) had positive blood cultures at DT initiation, related to blood culture incubation time. Median bacteremia duration after DT was two days (IQR 1-3). Two serious adverse events (5.7%), both encephalopathy, were reported. Seven patients (20%) died, five related to SAB or its management.

CONCLUSIONS

Due to blood culture delays, 40% of the patients had already cleared bacteremia before DT initiation. Further studies are needed to better define the role of this strategy and to identify the patients most likely to benefit.