2448. In vitro Activity of Ceftazidime-avibactam against Enterobacteriaceae Causing Intra-abdominal, Urinary Tract and Lower Respiratory Tract Infections Collected in Latin America as Part of the INFORM Global Surveillance Program, 2012-2016
Session: Poster Abstract Session: Treatment of AMR Infections
Saturday, October 6, 2018
Room: S Poster Hall
  • Pfizer_P78_Long CAZ-AVI LA by site_IDSA 2018_FINAL.pdf (318.6 kB)
  • Background: The dissemination of multi-drug resistant Enterobacteriaceae (MDR Eba) threatens the treatment of Gram-negative infections. Ceftazidime-avibactam (CAZ-AVI) is a novel antimicrobial with activity against Eba producing Class A, C and some Class D β-lactamases. This study evaluates the in vitro activity of CAZ-AVI against Eba isolates from urinary tract infections (UTI), intra-abdominal infections (IAI) and lower respiratory tract infections (LRTI) gathered in Latin America (LA) from 2012-2016.

    Methods: 7,037 non-duplicate Eba were collected from UTI, IAI or LRTI in 26 sites in 6 countries in LA, as a part of the INFORM surveillance study from 2012-2016. Susceptibility testing was by broth microdilution using CLSI 2018 breakpoints. CAZ-AVI was tested with a fixed concentration of 4 µg/mL avibactam. Meropenem non-susceptibility prompted β-lactamase screening by PCR and sequencing.

    Results: CAZ-AVI demonstrated potent in vitro activity against Eba from UTIs, IAIs and LRTIs (99.6%, 99.8% and 99.5% susceptible, respectively). CAZ-AVI was active against colistin-resistant and MDR Eba as well as meropenem-non-susceptible Eba not encoding metallo-β-lactamases (96.5%, 98.4% and 99.4% susceptible, respectively) (Table).


    CAZ-AVI (%Susceptible, n)

    All (n)

    UTI (n)

    IAI (n)

    LRTI (n)

    Eba, All

    99.6% (7,037)

    99.6% (2,918)

    99.8% (2,401)

    99.5% (1,718)


    98.7% (2,110)

    98.4% (797)

    99.2% (709)

    98.5% (604)


    93.8% (372)

    93.2% (147)

    95.7% (116)

    92.7% (109)

    MEM-NS, MBL-negative

    99.4% (351)

    99.3% (138)

    99.1% (112)

    100% (101)


    96.5% (144)

    98.4% (63)

    97.3% (37)

    93.2% (44)


    98.4% (1,456)

    98.1% (591)

    98.8% (480)

    98.2% (385)

    Infection source: UTI, urinary tract; IAI, intra-abdominal tract; LRTI, lower respiratory tract. CAZ-AVI, ceftazidime-avibactam; CAZ, ceftazidime; MEM, meropenem; CST, colistin; MDR, multidrug resistant; MBL, metallo-β-lactamase; NS, non-susceptible; R, resistant.

    a Excludes Proteeae and Serratia spp; CST breakpoints are by EUCAST 2018.

    b MDR, resistant to agents from ≥3 classes.

    Conclusion: CAZ-AVI exhibited potent in vitro activity against Eba from UTIs, IAIs and LRTIs isolated in Latin America from 2012-2016 and provides a vital alternative to colistin and meropenem when MBLs are not present.

    Mark Estabrook, Ph.D1, Krystyna Kazmierczak, Ph.D1, Gregory G. Stone, Ph.D.2 and Dan Sahm, PhD3, (1)IHMA, Inc., Schaumburg, IL, (2)Pfizer, Inc., New York, NY, (3)International Health Management Associates, Inc., Schaumburg, IL


    M. Estabrook, Pfizer, Inc.: Consultant , Consulting fee . IHMA, Inc.: Employee , Salary .

    K. Kazmierczak, Pfizer Inc.: Consultant , Consulting fee . IHMA, Inc.: Employee , Salary .

    G. G. Stone, Pfizer Inc.: Employee , Salary . AstraZeneca: Former Employee and Shareholder , Salary .

    D. Sahm, Pfizer Inc.: Consultant , Consulting fee . IHMA, Inc.: Employee , Salary .

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.