title: Systematic PCR detection in culture-negative osteoarticular infections.
abstract: BACKGROUND
  Identification of microorganisms is crucial for the successful treatment of osteoarticular infections. Molecular methods are more sensitive than culture-dependent methods but may suffer from lack of specificity.
  
  
  METHODS
  We studied a large series of 3840 bone and joint culture-negative samples collected from 2308 patients hospitalized in Marseille University Hospitals from November 2007 to October 2009. The samples were systematically cultured for 15 days, and conventional broad-range polymerase chain reaction (PCR) (16S rDNA and 18S rDNA) as well as real-time PCR assays targeting human Bglobin, Staphylococcus aureus, and Kingella kingae were realized on one culture-negative specimen.
  
  
  RESULTS
  Specimens from 741 patients (32.1%) tested positive by culture, including 38 in which bacteria grew only after 6 days of incubation. PCR was positive in 141 (9%) culture-negative specimens. Microorganisms identified by PCR were classified into 2 groups: fastidious bacteria (n = 35), mostly anaerobes in adult patients, and K. kingae in children; and nonfastidious bacteria (n = 106), mostly S. aureus (32.7%). A discrepancy between a positive PCR result for S. aureus and a negative culture were explained by previous antibiotherapy in 31.4% of cases. Our study highlights the usefulness of systematic 16S rDNA gene PCR for the diagnosis of bone and joint infections in culture-negative patients, thus enabling the administration of specific antibiotic treatments.
  
  
  CONCLUSIONS
  We recommend the use of conventional broad-range PCR for culture-negative bone and joint specimens, as well as S. aureus-specific PCR for adults and K. kingae-specific PCR for children. 18S rDNA PCR should be reserved only for specific cases.
authors.affiliation: Faculté de Médecine, Aix-Marseille Université, Marseille, France.
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Levy
authors.forename: Pierre-Edouard
authors.initials: PE
authors.lastname: Fournier
authors.forename: Florence
authors.initials: F
authors.lastname: Fenollar
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000328:Adult; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D001424:Bacterial Infections / Q000175:diagnosis*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis* / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D012329:RNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012189:Retrospective Studies
chemical_list: D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: 16S rDNA PCR assay; Arthroplastic and osteosynthetic infection