1303. Comparison of Susceptibility Patterns for Acinetobacter spp. Infections among ICU Patients; TEST 2010-2012
Session: Poster Abstract Session: Below the Diaphragm
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • IDSA 1303.pdf (640.8 kB)
  • Background: Acinetobacter spp. (ASP) can cause serious infections, particularly among very ill hospitalized patients such as those in ICUs. This pathogen is difficult to treat based upon multiple resistance mechanisms that are common among this genus group, including acquired efflux pumps associated with multi-drug resistance (MDR). The susceptibility (S) percentages from a recent collection of ASP isolates from the TEST program in four geographic regions were examined from patients hospitalized in ICUs, regardless of age and with various sources of infection.

    Methods: A total of 1,590 unique ICU patient isolates were tested against a panel of broad spectrum antimicrobial agents during 2010-2012 including tigecycline (TIG), amikacin (AK), levofloxacin (LEVO) and several β-lactams. Isolates were tested by the local centers located in the Asia-Pacific, European, North and Latin American regions using CLSI broth microdilution, interpretation criteria and QC recommendations.

    Results: The MIC and S data are found in the table.

    Organism

    Drug

    MIC50

    MIC90

    %Sus.a

    %Int. a

    %Res. a

    ASP (1,590)

    AK

    32

    > 64

    45.3

    6.5

    48.2

     

    Cefepime

    32

    > 32

    35.6

    13.3

    51.1

     

    Ceftazidime

    > 16

    > 32

    32.9

    6.2

    60.9

     

    Ceftriaxone

    > 32

    > 64

    18.5

    17.3

    64.2

     

    LEVO

    8

    > 8

    34.5

    11.3

    54.2

     

    Meropenem

    8

    > 16

    45.4

    4.8

    49.8

     

    Minocycline

    1

    8

    79.2

    14.5

    6.3

     

    Pip-Tazo

    > 128

    > 128

    31.4

    6.4

    62.2

     

    TIG

    0.5

    2

    NA

    NA

    NA

    a CLSI breakpoint criteria; NA = no criteria for TIG.

    Conclusion: This collection of ASP isolates from patients in ICUs had very low susceptibility to the agents tested in this study. MIC50 values were in the resistant range for all drugs except for minocyline (MINO).  Although not indicated for ASP infections, TIG had the greatest in vitro activity (MIC90 value four-fold lower than MINO). Patients in ICUs are at significant risk of infections caused by opportunistic pathogens such as ASP which can cause infections in numerous organ systems. MDR ASP and the lack of antibiotics exhibiting good activity render such infections highly problematic in healthcare settings.

    Douglas Biedenbach, BS1, Stephen Hawser, PhD2, Meredith Hackel, PhD, MPH1, Daryl Hoban, PhD3, Samuel Bouchillon, MD3, Brian Johnson, BS4 and Heidi Leister-Tebbe, BS5, (1)International Health Management Associates, Inc., Schaumburg, IL, (2)IHMA Europe SÓrl, Epalinges, Switzerland, (3)Ihma, Inc., Schaumburg, IL, (4)IHMA, Inc., Schaumburg, IL, (5)Pfizer Inc., Collegeville, PA

    Disclosures:

    D. Biedenbach, None

    S. Hawser, None

    M. Hackel, None

    D. Hoban, None

    S. Bouchillon, None

    B. Johnson, None

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

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