1847. Antimicrobial Susceptibility Profiles of Key Intra-abdominal (IAI) Bacterial Isolates from North America: 2011-2015
Session: Poster Abstract Session: Antibacterial Susceptibility Surveillance
Saturday, October 29, 2016
Room: Poster Hall
Posters
  • P09_IAI_IDweek_Pfizer_2016_v1 final.pdf (262.5 kB)
  •   Background: Enterobacteriaceae and non-enteric gram-negative pathogens cause serious infections among hospitalized patients, including intra-abdominal infections (IAI). Tigecycline Evaluation Surveillance Trial (TEST) program data were used to evaluate the in vitro activity of several key drugs against pathogens causing IAI among patients from North America. Methods:  378 cumulative sites from North America between 2011 and 2015 contributed Enterobacteriaceae, P. aeruginosa, and A. baumannii isolates collected from IAI sources during 2011-2015. Species identification and testing by broth microdilution was performed locally according to CLSI guidelines. Categorical interpretation of results was done using CLSI or FDA breakpoint (i.e. tigecycline) criteria where appropriate. Results: The activities of the various drugs according to organism groups are provided in the table below.

    Enterobacteriaceae (1021) ESBL +* (63) P. aeruginosa (103) A. baumannii (16)
    Drug %S MIC50 MIC90 %S MIC50 MIC90 %S MIC50 MIC90 %S MIC50 MIC90
    Tigecycline 97.0 0.25 1 95.2 0.25 1 na** 8 > 8 na 0.12 2
    Amikacin 99.6 2 4 100 4 8 98.1 4 8 81.3 2 > 64
    Cefepime 90.9 ≤  0.5 2 19.1 >32 > 32 79.6 4 16 68.8 1 > 32
    Levofloxacin 83.2 0.06 > 8 19.1 > 8 > 8 65.1 1 > 8 62.5 0.12 > 8
    Meropenem 98.1 ≤  0.06 0.12 92.1 ≤  0.06 1 75.7 1 16 68.8 0.5 > 16
    Pip-Tazo 89.5 2 32 77.8 4 > 128 77.7 4 64 62.5 0.25 > 128

    *E. coli (28), K. oxytoca (10), K. pneumoniae (8)

    **na: no CLSI or FDA breakpoints available

     Conclusion:  Based on percent susceptibility, tigecycline, amikacin, and meropenem were the most active agents against IAI Enterobacteriaceae, including those with an ESBL phenotype. The antimicrobial susceptibility pattern observed among the two non-enteric species underscore the need for IDSA recommended combination therapies and continued monitoring of antimicrobial activities among these clinical important microorganisms from IAIs in North America.

     

    Douglas Biedenbach, MS1, Martha Renteria, MD1, Heidi Leister-Tebbe, BSN2 and Dan Sahm, PhD1, (1)International Health Management Associates, Inc., Schaumburg, IL, (2)Pfizer, Inc., Collegeville, PA

    Disclosures:

    D. Biedenbach, IHMA, Inc.: Independent Contractor , Research support

    M. Renteria, IHMA, Inc.: Independent Contractor , Research support

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

    D. Sahm, IHMA, Inc.: Independent Contractor , Research support

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.