Program Schedule

Rapid Testing using Verigene® Microarray in Combination with Antimicrobial Stewardship Intervention in Gram-negative Bacteremia

Session: Poster Abstract Session: Antibiotic Stewardship
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
  • Background: Rapid identification of organism and resistance is paramount for targeted treatment in serious blood stream-infections (BSI).  Verigene® Gram-Negative Blood Culture Test (BC-GN) is a multiplex, automated nucleic acid test for the identification of a broad panel of Gram-negative (GN) organisms and resistance markers from blood culture bottle positivity with a turnaround time of approximately 2 hours.  We evaluated the Verigene® BC-GN assay in combination with theoretical antimicrobial stewardship team (AST) intervention in GN BSIs.

    Methods: Clinical isolates from adult patients at the University Maryland Medical Center with GN bacteremia from January 2012 to June 2012 were included.  Blood culture bottles were spiked with clinical isolates and processed by Verigene® BC-GN.  AST reviewed charts along with Verigene® result and recommended antibiotics using derived algorithms. The time interval included in analysis was time of Gram stain report until 48 hours after susceptibility results.  The intervention group’s (Verigene® with AST) antibiotic recommendation was theoretically implemented at 3 hours from actual Gram stain report, and compared with the control group’s actual antibiotic administration times obtained from the chart, using Student's t-test.

    Results: A total of 117 isolates were tested, demonstrating 97.6% sensitivity, 99.6% specificity and overall concordance rate of 95.7% (112/117) for organism identification.  Half of the Enterobacteriaceae isolates resistant or intermediate to ceftriaxone were detected as CTX-M (5/10) and all of the MDR A. baumannii were detected as OXA (7/7).  The intervention group had a significantly shorter mean duration to both effective (1.4 vs 6.6 hours, P < 0.01) and optimal (6.7 vs 47.7 hours, P < 0.01) antibiotic therapy.  Using proportional hazards regression, we found that the intervention group was significantly more likely to receive timely optimal antibiotic therapy compared to controls (hazard ratio 1.5, P = 0.01).

    Conclusion: Our study demonstrated a potential decreased time to both effective and optimal antibiotic therapy in GN BSI using combined intervention of rapid testing and AST recommendation.  Prospective studies are needed to further validate this strategy.

    Jacqueline T. Bork, MD1, Surbhi Leekha, MBBS, MPH1,2, Emily Heil, PharmD1, Rilwan Badamas, PharmD Candidate3 and J. Kristie Johnson, PhD4,5, (1)Infectious Diseases, University of Maryland Medical Center, Baltimore, MD, (2)Epidemiology and Public Health, University of Maryland, Baltimore School of Medicine, Baltimore, MD, (3)Pharmacy, University of Maryland School of Medicine, Baltimore, MD, (4)Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, (5)Department of Pathology, University of Maryland School of Medicine, Baltimore, MD


    J. T. Bork, None

    S. Leekha, None

    E. Heil, None

    R. Badamas, None

    J. K. Johnson, Nanosphere: Investigator, Research support
    Bio-Fire: Investigator, Research support
    OpGen: Investigator, Research support

    Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

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