1851. The susceptibility of Eravacycline and Comparators to Global Isolates of Acinetobacter baumannii
Session: Poster Abstract Session: Antibacterial Susceptibility Surveillance
Saturday, October 29, 2016
Room: Poster Hall
Posters
  • ID Week-2016New Orleans-Eravacycline-HS.pdf (359.9 kB)
  • Background: Eravacycline (ERV) is a novel, fully synthetic fluorocycline antibiotic of the tetracycline class being developed for the treatment of serious infections, including those caused by multidrug-resistant (MDR) pathogens. The purpose of this study was to evaluate the activity of ERV and comparators against global, non-duplicate isolates of carbapenem-resistant Acinetobacter baumannii (CRAB).

    Methods: Clinical isolates (n=300) were collected from various body sites in patients in nine mainly European countries from 2005-2015. Antimicrobial susceptibility testing was performed by broth microdilution in cation-adjusted Mueller–Hinton broth according to CLSI guidelines. The concentration ranges tested in 2-fold dilutions were: ERV, 0.015–16 mg/L; amikacin, 1–128 mg/L; imipenem, 1-128 mg/L; levofloxacin, 0.25–32 mg/L; meropenem, 0.25–32 mg/L; minocycline, 0.125-16 mg/L; doxycycline, 0.125-16 mg/L; sulbactam, 0.25-32 mg/L; tigecycline, 0.126-16 mg/L; and tobramycin, 0.25-32 mg/L. Susceptibility was determined using CLSI 2015 breakpoints. Based on rep-PCR and MLST, isolates represented 8 worldwide clonal lineages and included 232 isolates with blaOXA-23-like, 18 isolates with blaOXA-40-like, 28 isolates with blaOXA-58-like and 22 isolates with overexpression of intrinsic blaOXA-51.

    Results: The ERV MIC50/90 values for all isolates were 0.5/1 mg/L. Comparatively, tigecycline, minocycline and doxycycline MIC50/90 values were 1/2, 4/8, 32/>32 mg/L, respectively. One or 19 strains had susceptibility of ≥4 mg/L to eravacycline and tigecycline, respectively, while 28 strains had a MIC of 16 mg/L.

    Organism (n)

    Eravacycline

    Tigecycline

    Minocycline

    MIC50/90

    MIC range

    MIC50/90

    MIC range

    MIC50/90

    MIC range

    A. baumannii (300)

    0.5/1

    0.031 - 8

    1/2

    0.125-8

    4/8

    ≤0.063-16

    Conclusion: ERV had the best in vitro potency, including isolates that were pan-resistant to sulbactam, imipenem/meropenem, levofloxacin, and amikacin/tobramycin, compared to other compounds. ERV may be a therapeutic option for treatment of multidrug-resistant A. baumannii
    .

    Harald Seifert, MD1, Danuta Stefanik, BS1, Paul Higgins, PhD1 and Joyce Sutcliffe, PhD2, (1)Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Köln, Germany, (2)Tetraphase Pharmaceuticals, Inc., Watertown, MA

    Disclosures:

    H. Seifert, Tetraphase Pharmaceuticals, Inc.: Scientific Advisor , Consulting fee

    D. Stefanik, None

    P. Higgins, None

    J. Sutcliffe, Tetraphase Pharmaceuticals: Employee , Salary

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