title: Evaluation of a commercial multiplex PCR (Unyvero i60®) designed for the diagnosis of bone and joint infections using prosthetic-joint sonication.
abstract: BACKGROUND
  The development of sonication protocols over the last few years has improved the sensitivity of conventional cultures for the diagnosis of prosthetic-joint infection (PJI). However, the development of a new, specifically designed kit for the molecular diagnosis of PJI could provide a major improvement in this field.
  
  
  METHODS
  Prostheses retrieved from patients who underwent implant removal from May 2014 to May 2015 were sent for culture, and processed according to a previously defined protocol that included sonication. Furthermore, 180 microlitres of sonication fluid were used to carry out the multiplex PCR test (Unyvero i60 system®). A comparison of the sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, was performed. The study was approved by the Clinical Research Ethics Committee.
  
  
  RESULTS
  The analysis included 88 prostheses from 68 patients (1.29 prostheses/patient). The type of prostheses studied were knee (n=55), total hip (n=26), partial hip (n=5), and shoulder (n=2). Twenty-nine patients were diagnosed with a PJI (15 delayed, 12 acute, and 2 haematogenous infections). In 24 cases, the result of the PCR was positive, all but 1 corresponding to patients with clinical criteria of PJI. Nine resistance mechanisms were detected from 5 samples. The Unyvero i60 system®showed slightly better results than traditional culture in terms of specificity and PPV.
  
  
  CONCLUSIONS
  The Unyvero i60 system®may play a role in rapid diagnosis of PJI, due to its high specificity and PPV. However, despite these results, cultures have to be performed to detect organisms not detected by the system.
authors: Department of Clinical Microbiology, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Laura
authors: L
authors: Prieto-Borja
authors: Department of Clinical Microbiology, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Graciela
authors: G
authors: Rodriguez-Sevilla
authors: Department of Orthopaedic Surgery, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Alvaro
authors: A
authors: Auñon
authors: Department of Clinical Microbiology, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Concepción
authors: C
authors: Pérez-Jorge
authors: Department of Orthopaedic Surgery, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Enrique
authors: E
authors: Sandoval
authors: Department of Internal Medicine-Emergency, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Joaquín
authors: J
authors: Garcia-Cañete
authors: Department of Clinical Microbiology, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Ignacio
authors: I
authors: Gadea
authors: Department of Clinical Microbiology, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Ricardo
authors: R
authors: Fernandez-Roblas
authors: Department of Internal Medicine-Emergency, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain.
authors: Antonio
authors: A
authors: Blanco
authors: Department of Clinical Microbiology, IIS-Fundación Jiménez Díaz, UAM, Av. Reyes Católicos 2, 28040 Madrid, Spain. Electronic address: jestebanmoreno@gmail.com.
authors: Jaime
authors: J
authors: Esteban
mesh_terms: D000368:Aged; D001847:Bone Diseases / Q000175:diagnosis* / Q000382:microbiology*; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis* / Q000382:microbiology*; D008297:Male; D060885:Multiplex Polymerase Chain Reaction; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology*; D013010:Sonication
keywords: Diagnosis; Diagnosis PCR múltiple; Diagnóstico; Diagnóstico molecular; Infección de prótesis articular; Molecular diagnosis; Multiplex PCR; Prosthetic-joint infection; Sonicación; Sonication