Background. Several series predicting the prognosis of staphylococcal prosthetic joint infection (PJI) managed with debridement, antibiotics, and implant retention (DAIR) have been published, but some of their conclusions are controversial. At present, little is known regarding the efficacy of the different antibiotics that are used or their ability to eliminate methicillin-resistant S. aureus (MRSA) infection. Methods. This was a retrospective, multicenter, observational study of cases of PJI by S. aureus that were managed with DAIR (2003–2010). Cases were classified as failures when infection persistence/relapse, death, need for salvage therapy, or prosthesis removal occurred. The parameters that predicted failure were analyzed with logistic and Cox regression. Results. Out of 345 episodes (41% men, 73 years), 81 episodes were caused by MRSA. Fifty-two were hematogenous, with poorer prognoses, and 88% were caused by methicillin-susceptible S. aureus (MSSA). Antibiotics were used for a median of 93 days, with similar use of rifampin-based combinations in MSSA- and MRSA-PJI. Failure occurred in 45% of episodes, often early after debridement. The median survival time was 1257 days. There were no overall prognostic differences between MSSA- and MRSA-PJI, but there was a higher incidence of MRSA-PJI treatment failure during the period of treatment (HR 2.34), while there was a higher incidence of MSSA-PJI treatment failure after therapy. Rifampin-based combinations exhibited an independent protective effect. Other independent predictors of outcome were polymicrobial, inflammatory, and bacteremic infections requiring more than 1 debridement, immunosuppressive therapy, and the exchange of removable components of the prosthesis. Conclusions. This is the largest series of PJI by S. aureus managed with DAIR reported to date. The success rate was 55%. The use of rifampin may have contributed to homogenizing MSSA and MRSA prognoses, although the specific rifampin combinations may have had different efficacies.

The aim of our study was to characterize the etiology of prosthetic joint infections (PJIs)—including multidrug-resistant organisms (MDRO)—by category of infection. A multicenter study of 2544 patients with PJIs was performed. We analyzed the causative microorganisms according to the Tsukayama’s scheme (early postoperative, late chronic, and acute hematogenous infections (EPI, LCI, AHI) and “positive intraoperative cultures” (PIC)). Non-hematogenous PJIs were also evaluated according to time since surgery: 12 months. AHIs were mostly caused by Staphylococcus aureus (39.2%) and streptococci (30.2%). EPIs were characterized by a preponderance of virulent microorganisms (S. aureus, Gram-negative bacilli (GNB), enterococci), MDROs (24%) and polymicrobial infections (27.4%). Conversely, coagulase-negative staphylococci (CoNS) and Cutibacterium species were predominant in LCIs (54.5% and 6.1%, respectively) and PICs (57.1% and 15.1%). The percentage of MDROs isolated in EPIs was more than three times the percentage isolated in LCIs (7.8%) and more than twice the proportion found in AHI (10.9%). There was a significant decreasing linear trend over the four time intervals post-surgery for virulent microorganisms, MDROs, and polymicrobial infections, and a rising trend for CoNS, streptococci and Cutibacterium spp. The observed differences have important implications for the empirical antimicrobial treatment of PJIs.

We aimed to determine whether daptomycin plus fosfomycin provides higher treatment success than daptomycin alone for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and endocarditis. A randomized (1:1) phase 3 superiority, open-label, and parallel group clinical trial of adult inpatients with MRSA bacteremia was conducted at 18 Spanish hospitals. Patients were randomly assigned to receive either 10 mg/kg of daptomycin intravenously daily plus 2 g of fosfomycin intravenously every 6 hours, or 10 mg/kg of daptomycin intravenously daily. Primary endpoint was treatment success 6 weeks after the end of therapy. Of 167 patients randomized, 155 completed the trial and were assessed for the primary endpoint. Treatment success at 6 weeks after the end of therapy was achieved in 40 of 74 patients who received daptomycin plus fosfomycin and in 34 of 81 patients who were given daptomycin alone (54.1% vs 42.0%; relative risk, 1.29 [95% confidence interval, .93–1.8]; P = .135). At 6 weeks, daptomycin plus fosfomycin was associated with lower microbiologic failure (0 vs 9 patients; P = .003) and lower complicated bacteremia (16.2% vs 32.1%; P = .022). Adverse events leading to treatment discontinuation occurred in 13 of 74 patients (17.6%) receiving daptomycin plus fosfomycin, and in 4 of 81 patients (4.9%) receiving daptomycin alone (P = .018). Daptomycin plus fosfomycin provided 12% higher rate of treatment success than daptomycin alone, but this difference did not reach statistical significance. This antibiotic combination prevented microbiological failure and complicated bacteremia, but it was more often associated with adverse events. NCT01898338.

Prosthetic joint infection (PJI) is a severe complication that occurs in 0.5–3% of arthroplasties [ 1 x 1 Pulido, L, Ghanem, E, Joshi, A, Purtill, JJ, and Parvizi, J. Periprosthetic joint infection: the incidence, timing, and predisposing factors. Clin Orthop Relat Res. 2008; 466: 1710–1715 Crossref | PubMed | Scopus (534) | Google Scholar See all References , 2 x 2 Soriano, A, Bori, G, García‐Ramiro, S et al. Timing of antibiotic prophylaxis for primary total knee arthroplasty performed during ischemia. Clin Infect Dis. 2008; 46: 1009–1014 Crossref | PubMed | Scopus (40) | Google Scholar See all References , 3 x 3 Yokoe, DS, Avery, TR, Platt, R, and Huang, SS. Reporting surgical site infections following total hip and knee arthroplasty: impact of limiting surveillance to the operative hospital. Clin Infect Dis. 2013; 57: 1282–1288 Crossref | PubMed | Scopus (38) | Google Scholar See all References ] and staphylococci are the most frequently isolated microorganisms [ 4 x 4 Moran, E, Byren, I, and Atkins, BL. The diagnosis and management of prosthetic joint infections. J Antimicrob Chemother. 2010; 65: iii45–iii54 Crossref | PubMed | Scopus (98) | Google Scholar See all References 4 ]. Coagulase-negative staphylococci account for 30–41% and Staphylococcus aureus for 12–39%. Gram-negative organisms are less common than Gram-positive, causing around 10% of cases [ 5 x 5 Peel, TN, Cheng, AC, Buising, KL, and Choong, PFM. Microbiological aetiology, epidemiology, and clinical profile of prosthetic joint infections: are current antibiotic prophylaxis guidelines effective?. Antimicrob Agents Chemother. 2012; 56: 2386–2391 Crossref | PubMed | Scopus (88) | Google Scholar See all References 5 ]. Among Gram-positive bacteria, Enterococcus sp. account for 3–10% [ 6 x 6 Berbari, EF, Osmon, DR, Duffy, MCT et al. Outcome of prosthetic joint infection in patients with rheumatoid arthritis: the impact of medical and surgical therapy in 200 episodes. Clin Infect Dis. 2006; 42: 216–223 Crossref | PubMed | Scopus (93) | Google Scholar See all References , 7 x 7 Marculescu, CE, Berbari, EF, Hanssen, AD et al. Outcome of prosthetic joint infections treated with debridement and retention of components. Clin Infect Dis. 2006; 42: 471–478 Crossref | PubMed | Scopus (273) | Google Scholar See all References , 8 x 8 Moran, E, Masters, S, Berendt, AR et al. Guiding empirical antibiotic therapy in orthopaedics: the microbiology of prosthetic joint infection managed by debridement, irrigation and prosthesis retention. J Infect. 2007; 55: 1–7 Abstract | Full Text | Full Text PDF | PubMed | Scopus (126) | Google Scholar See all References ]; however, the isolation of enterococci has been associated with a worse outcome [ 9 x 9 Soriano, A, Garcia, S, Bori, G et al. Treatment of acute post‐surgical infection of joint arthroplasty. Clin Microbiol Infect. 2006; 12: 930–933 Abstract | Full Text | Full Text PDF | PubMed | Scopus (82) | Google Scholar See all References , 10 x 10 Lora‐Tamayo, J, Euba, G, Ribera, A et al. Infected hip hemiarthroplasties and total hip arthroplasties: differential findings and prognosis. J Infect. 2013; 67: 536–544 Abstract | Full Text | Full Text PDF | PubMed | Scopus (13) | Google Scholar See all References ] probably due to the tolerance of enterococci to different classes of antibiotics. The largest case series was published by El Helou et al. [ 11 x 11 El Helou, OC, Berbari, EF, Marculescu, CE et al. Outcome of enterococcal prosthetic joint infection: is combination systemic therapy superior to monotherapy?. Clin Infect Dis. 2008; 47: 903–909 Crossref | PubMed | Scopus (34) | Google Scholar See all References 11 ] where they described 50 cases treated in one institution over 30 years; however, polymicrobial infections were excluded from the analysis and recent data suggest that PJI are frequently polymicrobial—probably due to improvements in sampling and microbiological methods.