Streptococcal and Staphylococcus aureus prosthetic joint infections: are they really different?

BACKGROUND: Staphylococci and streptococci are the most frequent pathogens isolated from prosthetic joint infections (PJIs). The aim of this study was to analyze the outcome of streptococcal and methicillin-susceptible Staphylococcus aureus (MSSA) PJIs. METHODS: All monomicrobial streptococcal and MSSA PJIs managed in a French Referral Center (2010-2017) were sampled from the prospective PJIs cohort study. The primary outcome of interest was the cumulative reinfection-free survival at a 2-year follow-up. RESULTS: Two hundred and nine patients with 91 streptococcal and 132 staphylococcal infections were analyzed. Patients with streptococcal PJI were older, and infection was more frequently hematogenous. Reinfection-free survival rates at 2-years after all treatment strategies were higher for patients with streptococcal PJI (91% vs 81%; P = .012), but differed according to the strategy. After exchange arthroplasty, no outcome differences were observed (89% vs 93%; P = .878); after debridement, antibiotics and implant retention (DAIR), the reinfection-free survival rate was higher for patients with streptococcal PJI (87% vs 60%; P = .062). For patients managed with prolonged suppressive antibiotic therapy (SAT) alone, those with streptococcal PJIs had a 100% infection-free survival (100% vs 31%; P < .0001). CONCLUSIONS: Reinfection-free survival after DAIR and SAT was better for patients with streptococcal than those with MSSA PJIs. No difference was observed after prosthesis exchange.