Do you use combination therapy for persistent MSSA bacteremia?

I don’t think I’ve ever come across a situation where the problem wasn’t source control…

A wide variety of combinations have been used (Chastain et al., PMID 36946576), but there is no solid convincing evidence favoring any single one. In addition, there is strong evidence indicating a clinical (as opposed to, perhaps, a microbiological benefit). I have, however, used cefazolin together...

I've done this in a couple of cases when desperate. Excellent comments and references above, including Dr. @Dr. First Last's mention of the CID 2020 case series.

One more single case report to mention: Sakoulas et al., PMID 27572414

Cefazolin/Erta likewise successfully cleared persistent MSSA bacterem...

I usually do not have a problem with single therapy. Though if bioburden is high and the patient is critical, I tend to use Nafcillin first, then may consider switching to Cefazolin (more convenient for OPAT) once clinically improved, though source control is still the more important first step.