228. Sonication of Cardiovascular Implantable Electronic Devices to Enhance Microbial Detection
Session: Poster Abstract Session: Diagnostic Microbiology
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • IDSA 2013 Poster.pdf (417.6 kB)
  • Background:

    The cardiovascular implantable electronic device (CIED) infection rate is rising disproportionately to the rate of device implantation. Identification of infecting pathogens is not always possible using current laboratory techniques. We conducted a prospective study to determine whether device vortexing-sonication followed by culture of dislodged and disaggregated biofilms would enhance microbial detection as compared to traditional culture of swabs or resected generator pocket tissue.  

    Methods:

    Forty-two subjects with non-infected devices and thirty-five subjects with infected devices were prospectively enrolled over a period of 12 months. One swab from the device pocket, another swab from the device surface, a pocket tissue specimen and the CIED system (generator plus leads) were collected from each subject. The CIED was processed using vortexing-sonication in 400 ml Ringer’s solution and the resultant sonicate fluid was cultured. Swabs and tissues were cultured using routine methods. Tissue/swab growth was considered to be significant when bacterial colonies grew on ≥2 quadrants of the culture plate and device growth when ≥20 colonies/10 ml sonicate fluid were isolated.

    Results:

    In the non-infected group, 5% [95% confidence interval (CI) 1% - 16%] of sonicate fluids and tissues and 2% (CI 0% - 12%) of swabs yielded significant growth (p = 0.3173). In the infected group, significant bacterial growth was observed in 54% (CI 38% - 69%) of sonicate fluids, 20% (CI 10% - 36%) of pocket swabs and 9% (CI 3% - 22%) of tissues and device surface swabs (p < 0.0001 and p = 0.0013 respectively).

    Conclusion:

    Vortexing-sonication of the CIED led to a significant increase in the sensitivity of culture results without decreasing specificity as compared to culture of swab or tissue specimens. This strategy should be useful in clinical practice because pathogen identification with in vitro susceptibility testing are pivotal in selecting optimal antimicrobial therapy in CIED infections.

    Avish Nagpal, MD1, Robin Patel, MD, FIDSA, FRCP(C), D(ABMM), FACP, F(AAM)2, Kerryl Greenwood-Quaintance, MS3, David Lynch4, Joseph J. Maleszewski, MD5, Paul A. Friedman, MD6, David Hayes, MD6, Larry M. Baddour, MD7 and Muhammad R. Sohail, MD8, (1)Infectious Diseases, Mayo Clinic, Rochester, MN, (2)Divisions Of Clinical Microbiology and Infectious Diseases, Mayo Clinic, Rochester, MN, (3)Microbiology, Mayo Clinic, Rochester, MN, (4)Mayo Clinic, Rochester, MN, (5)Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, (6)Cardiovascular Diseases, Mayo Clinic, Rochester, MN, (7)Department of Medicine, Division of Infectious Diseases, Mayo Clinic, Rochester, MN, (8)Mayo School of Graduate Medical Education, Rochester, MN

    Disclosures:

    A. Nagpal, None

    R. Patel, Pfizer: Investigator, Research grant
    Pradama : Investigator, Grant recipient
    Astellas: Investigator, Grant recipient
    Tornier: Investigator, Grant recipient
    Pocared: Investigator, Research grant

    K. Greenwood-Quaintance, None

    D. Lynch, None

    J. J. Maleszewski, None

    P. A. Friedman, None

    D. Hayes, None

    L. M. Baddour, None

    M. R. Sohail, None

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