Staphylococcus epidermidis implant-associated bone and joint infections: high rates of multiresistance associated...

Staphylococcus epidermidis is a leading pathogen of implant-associated bone and joint infection (BJI) and is frequently resistant to multiple antibiotics. In this study, we aimed to analyse risk factors for multiresistance and the association of multiresistance with treatment outcomes in patients with S. epidermidis implant-associated BJI.

We performed a single-centre cohort study including patients with implant-associated BJI due to S. epidermidis at the University Hospital Basel, Switzerland, between January 2013 and December 2020. Risk factors for multiresistance and their association with treatment failure, the primary outcome, were assessed using logistic models and piecewise Cox models, respectively.

Of 1776 patients screened with intraoperative S. epidermidis, 279 were eligible, of which 250 patients (90%) were included with implant-associated BJI: Half had a monomicrobial implant-associated BJI (125 of 250) and 56% (141 of 250) presented with multiresistant S. epidermidis. Previous antibiotic treatment exhibited the strongest association with multiresistance in S. epidermidis implant-associated BJI (adjusted ORs, 2.13; 95% CI: 1.21-3.81). Overall, 32% of patients (80 of 250) experienced a treatment failure. Multiresistance was associated with treatment failure occurring more than 2 wk after revision surgery (adjusted HR, 4.29; 95% CI" 1.51-12.19).

Our results suggest that previous antibiotic treatments select for multiresistant S. epidermidis, which increases the risk of treatment failure in implant-associated BJI. This study emphasizes the need for prudent antibiotic use and calls for new strategies against this still underestimated pathogen.