1178. Fluoroquinolone Resistance among Enterobacteriaceae from U.S. Medical Centers between 2011 and 2014
Session: Poster Abstract Session: Resistance Mechanisms
Friday, October 9, 2015
Room: Poster Hall
Posters
  • Pfizer_P33_IDSA 2015_USA_FQR Enterics_v01_final [Read-Only].pdf (87.3 kB)
  • Background: Since the introduction of quinolones in 1962, bacterial resistance has been on the rise. The development of fluoroquinolones (FQ), provided a broader spectrum of activity against both gram-negative and –positive pathogens. However, there has been a significant increase of resistance to FQ , particularly Enterobacteriaceae (ENT). This data from the Tigecycline Evaluation Surveillance Trial (TEST) program provides recent data on FQ resistance rates in ENT from isolates collected in hospitals located in the United States. Methods: A total of 1756 levofloxacin non-susceptible (LVX-NS) Enterobacteriaceae isolates from three species groups were collected from 130 U.S. hospitals between 2011 and 2014. MIC50/90 and percent susceptible (%S) results were determined against LVX-NS isolates for cefepime (FEP), meropenem (MEM), piperacillin/tazobactam (TZP) and tigecycline (TGC) using CLSI broth microdilution methods and interpretative criteria. Results: The overall percentage of LVX-NS ENT during this four year study was 17.1%. The following table displays in vitro testing results for LVX-NS ENT against comparative agents.

    Drug

    Species group (n/%LVX-NS)

    Enterobacter spp. (153/4.9%)

    E. coli (1171/32.4%)

    Klebsiella spp. (426/12.1%)

    MIC50/90

    %S

    MIC50/90

    %S

    MIC50/90

    %S

    FEP

    4/>32

    40.5

    ≤0.5/>32

    73.0

    16/>32

    32.6

    MEM

    0.12/4

    86.7

    ≤0.06/0.12

    98.6

    0.12/>16

    67.5

    TZP

    64/>128

    42.5

    2/16

    90.0

    128/>128

    43.4

    TGC

    1/4

    72.6

    0.12/0.5

    99.7

    1/4

    89.9

    Conclusion: FQ resistance was much higher among E. coli compared to Klebsiella spp. and Enterobacter spp. TGC, TZP and MEM were most active against LVX-NS E. coli at a %S greater than or equal to 90%. TGC was also the most active agent tested against Klebsiella spp and E. coli. MEM and TGC had equivalent potency against Enterobacter spp. The increasing rate of FQ-NS ENT is concerning and requires continued monitoring of alternative therapeutic choices which are often co-resistant among this subset of bacterial pathogens.

    Brian Johnson, BS1, Jack Johnson, MS, MBA1, Samuel Bouchillon, MD1, Meredith Hackel, PhD, MPH1, Dan Sahm, PhD1, Douglas Biedenbach, MS1 and Heidi Leister-Tebbe, BSN2, (1)International Health Management Associates, Inc., Schaumburg, IL, (2)Pfizer, Inc., Collegeville, PA

    Disclosures:

    B. Johnson, IHMA, Inc.: Independent Contractor , Consulting fee

    J. Johnson, IHMA, Inc.: Independent Contractor , Consulting fee

    S. Bouchillon, IHMA, Inc.: Independent Contractor , Consulting fee

    M. Hackel, IHMA, Inc.: Independent Contractor , Consulting fee

    D. Sahm, IHMA, Inc.: Independent Contractor , Consulting fee

    D. Biedenbach, IHMA, Inc.: Independent Contractor , Consulting fee

    H. Leister-Tebbe, Pfizer, Inc.: Employee , Salary

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.