title: Detection of bacteria with molecular methods in prosthetic joint infection: sonication fluid better than periprosthetic tissue.
abstract: Background and purpose - The correct diagnosis of prosthetic joint infection (PJI) can be difficult because bacteria form a biofilm on the surface of the implant. The sensitivity of culture from sonication fluid is better than that from periprosthetic tissue, but no comparison studies using molecular methods on a large scale have been performed. We assessed whether periprosthetic tissue or sonication fluid should be used for molecular analysis. Patients and methods - Implant and tissue samples were retrieved from 87 patients who underwent revision operation of total knee or total hip arthroplasty. Both sample types were analyzed using broad-range (BR-) PCR targeting the 16S rRNA gene. The results were evaluated based on the definition of periprosthetic joint infection from the Workgroup of the Musculoskeletal Infection Society. Results - PJI was diagnosed in 29 patients, whereas aseptic failure was diagnosed in 58 patients. Analysis of sonication fluid using BR-PCR detected bacteria in 27 patients, whereas analysis of periprosthetic tissue by BR-PCR detected bacteria in 22 patients. In 6 of 7 patients in whom BR-PCR analysis of periprosthetic tissue was negative, low-virulence bacteria were present. The sensitivity and specificity values for periprosthetic tissue were 76% and 93%, respectively, and the sensitivity and specificity values for sonication fluid were 95% and 97%. Interpretation - Our results suggest that sonication fluid may be a more appropriate sample than periprosthetic tissue for BR-PCR analysis in patients with PJI. However, further investigation is required to improve detection of bacteria in patients with so-called aseptic failure.
authors.affiliation: a Faculty of Health Sciences , University of Primorska , Izola ;|b Medical Microbiology Department, National Laboratory of Health , Environment and Food , Koper ;
authors.forename: Mitja
authors.initials: M
authors.lastname: Rak
authors.affiliation: b Medical Microbiology Department, National Laboratory of Health , Environment and Food , Koper ;
authors.forename: Martina
authors.initials: M
authors.lastname: KavčIč
authors.affiliation: c Valdoltra Orthopaedic Hospital , Ankaran , Slovenia.
authors.forename: Rihard
authors.initials: R
authors.lastname: Trebše
authors.affiliation: a Faculty of Health Sciences , University of Primorska , Izola ;|c Valdoltra Orthopaedic Hospital , Ankaran , Slovenia.
authors.forename: Andrej
authors.initials: A
authors.lastname: CőR
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000379:methods; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology; D012086:Reoperation; D013010:Sonication / Q000379:methods*
chemical_list: D004269:DNA, Bacterial