1142. Utilization of Ultrasonic Frequencies (Sonication) and Target Enriched Multiplex Polymerase Chain Reaction (TEM-PCR) in Identifying Elusive Prosthetic Joint Infections (PJI)
Session: Poster Abstract Session: Clinical Infectious Diseases: Bone and Joint, Skin and Soft Tissue
Friday, October 28, 2016
Room: Poster Hall
  • Sonication Poster_proof2.pdf (177.5 kB)
  • Background:  PJIs persist as an elusive complication in joint replacements demanding accuracy in identification of organisms for proper management of infections.

    Methods:  A retrospective chart review was conducted on 95 patients admitted with PJIs or infected orthopedic hardware.  Data collected included demographics, hardware/joint sonication, tissue samples, and a multiplex molecular testing panel (TEM-PCR) that detects 16 different bacterial targets and 7 drug resistant genes.

    Results:  The combination of 56 knees, 26 hips, 3 tibia nails, 2 ankles, 4 shoulders, 2 elbows, and 2 wrists PJI were reviewed. Mean age of 62 (21 -89) and 62% were female. Measured labs in 56% of patients showed mean ESR 30.26 (0 to >80), CRP 4.36 (<0.1 to 46) and WBC 9.45 (2-22).  Sonication was performed in 100% of patients while TEM-PCR and tissue cultures were performed in 76% and 65% of patients, respectively.   Previously undetected organisms from joints fluid were identified in 46% sonications, 44% TEM-PCR, and 31% tissue cultures.   Correlation of positive results between sonication and TEM-PCR equaled 35%, negative sonication/positive TEM-PCR 10%, and negative sonication/positive tissue cultures 20%.  Most common organisms detected with sonication were Staphylococcus epidermidis (36%), Staphylococcus aureus (17%), and Enterococcus faecalis (11%).  Comparatively, TEM-PCR detected Methicillin-resistant Staphylococcus aureus (MRSA) (25%), Escherichia coli (13%), and Enterococcus faecalis (12%), while tissue cultures produced Staphylococcus aureus (32%), Staphylococcus epidermidis (31%), and Enterococcus faecalis (7%).  There was co-detection of 2 or more bacterial targets on TEM-PCR, most common being Staphylococcus epidermidis and Enterococcus faecalis (7%).  TEM-PCR was the only method to identify Escherichia coli in 13% of patients.  Sonication culture and TEM-PCR combined detected organisms in 51% of patientsÕ while sonication and tissue cultures had positive cultures in 45%. Combining all methods detected organisms in 54% of patients.

    Conclusion:  Sonication and TEM-PCR demonstrated value in identifying elusive organisms as compared to standard methods.  Further studies are necessary to assess the practicality of sonication and TEM-PCR for identifying PJIs.


    Ali Hassoun, MD FIDSA FACP, Alabama Infectious Diseases Center, Huntsville, AL, Patti Hopkins, RN BSN MSHA, Surgical Service Line, Huntsville Hospital, Huntsville, AL and Michael Miller, PhD, The Orthopedic Center, Huntsville, AL


    A. Hassoun, None

    P. Hopkins, None

    M. Miller, None

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