Multiplex PCR in septic arthritis and periprosthetic joint infections microorganism identification: Results from the application of a new molecular testing diagnostic algorithm

• Published in: Journal of experimental orthopaedics Vol. 11; no. 3; pp. e12097 - n/a
• Main Authors: Ghirardelli, Stefano, Scaggiante, Federica, Troi, Christina, Valpiana, Pieralberto, Cristofolini, Giovanni, Aloisi, Giuseppe, Violante, Bruno, Russo, Arcangelo, Schaller, Sebastian, Indelli, Pier F.
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.07.2024; John Wiley and Sons Inc; Wiley
• Subjects: Algorithms; Antibiotics; Arthritis; BioFire; DAPRI; Drug resistance; Microorganisms; multiplex PCR; NGS; Original Paper; Pathogens; periprosthetic joint infections; PJI; septic arthritis; synovial fluid; total knee arthroplasty (TKA); multiplex PCR; total knee arthroplasty (TKA); septic arthritis; DAPRI; synovial fluid; BioFire; NGS; PJI; periprosthetic joint infections
• ISSN: 2197-1153; 2197-1153
• DOI: 10.1002/jeo2.12097

Purpose Pathogen identification is key in the treatment of septic arthritis (SA) and periprosthetic joint infections (PJI). This study evaluates the outcome of the application of a new, score‐based SA and PJI diagnostic algorithm, which includes the execution of molecular testing on synovial fluid. Methods A score‐based diagnostic algorithm, which includes serologic and synovial fluid markers determination using multiplex PCR (mPCR) and Next Generation Sequencing (NGS) molecular testing, has been applied to a consecutive series of patients with clinically suspected SA or PJI. Patients with a score ≥6 underwent synovial fluid molecular testing, together with traditional culture, to identify the pathogen and its genetically determined antibiotic resistance. Results One hundred and seventeen joints in 117 patients (62.5% women; average age 73 years) met the criteria for possible SA/PJI. The affected joint was the knee in 87.5% (joint replacement 66.5%; native joint 21%) and the hip in 12.5% (all replaced joints). 43/117 patients (36.7%) were ultimately diagnosed with SA/PJI. Among the various testing technologies applied, mPCR was the main determinant for pathogen identification in 63%, standard culture in 26%, and mNGS in 11%. Staphylococcus aureus and Enterococcus faecalis were the top two microorganisms identified by mPCR, while Staphylococcus epidermidis was the prevalent organism identified by NGS. mPCR detected the presence/absence of the genetically determined antibiotic resistance of all identified microorganisms. The average timeframe for pathogen identification was 3.13 h for mPCR, 4.5 days for culture, and 3.2 days for NGS. Conclusions Molecular diagnostic technologies represent an innovative screening for fast microorganism identification when a joint infection is clinically suspected. Level of Evidence Level IV, case series.