1177. Carbapenemases Found in Meropenem Non-Susceptible Enterobacteriaceae Collected as Part of the Tigecycline Evaluation Surveillance Trial (TEST) Program in 2011-2014
Session: Poster Abstract Session: Resistance Mechanisms
Friday, October 9, 2015
Room: Poster Hall
Posters
  • Pfizer_P27_IDSA_Carbapenemases 2011-2014_v1_final [Read-Only].pdf (442.6 kB)
  • Background: TEST monitors the in vitro activity of tigecycline and other antimicrobials against clinically-relevant pathogens collected globally. This study reports the b-lactamase content of a subset of meropenem non-susceptible (MEM-NS) TEST isolates collected in Europe (EUR), Latin America (LA), and North America (NA) in 2011-2014 and Middle East/ Africa (MEA) in 2011-2013.

    Methods: Non-duplicate clinical isolates were collected from defined infection sites. Susceptibility testing was performed by broth microdilution by the local laboratory using supplied panels and interpreted using CLSI breakpoints. MEM-NS phenotype (MIC > 1 mg/L) was confirmed at IHMA before screening isolates for b-lactamase genes encoding carbapenemases (Cpase), extended-spectrum b-lactamases (ESBL) and AmpC b-lactamases.

    Results: 1,456 MEM-NS Enterobacteriaceae (of 51,971 total) were collected globally. The b-lactamase content of a subset of 970 MEM-NS isolates collected in EUR (688), LA (46), NA (157), and MEA (79) was determined. The antimicrobial susceptibilities and Cpase content of these isolates are shown:

    % Susceptible; MIC901

    Region (n)

    TGC

    TZP

    LVX

    AMK

    All (51,971)

    97.3; 1

    85.0; 64

    79.5; > 8

    98.1; 4

    All MEM-NS (1456)

    91.6; 2

    10.6; > 128

    20.1; > 8

    70.6; 64

    Characterized MEM-NS (970)

    91.5; 2

    4.2; > 128

    14.9; > 8

    74.3; 32

    EUR (688)

    92.3; 2

    2.9; > 128

    12.5; > 8

    73.0; 32

    LA (46)

    95.7; 2

    8.7; > 128

    19.6; > 8

    73.9; > 64

    NA (157)

    93.6; 2

    10.2; > 128

    20.4; > 8

    87.9; 32

    MEA (79)

    78.5; 4

    1.3; > 128

    22.8; > 8

    59.5; > 64

    1TGC, tigecycline; TZP, piperacillin-tazobactam; LVX, levofloxacin; AMK, amikacin.

    \s

    No Cpase, no plasmid-encoded Cpase detected by PCR. Includes isolates carrying ESBLs, AmpC and chromosomally-encoded b-lactamases, presumably in combination with changes in membrane permeability.

    Conclusion: Regional differences in the incidence of Cpases and in the antimicrobial susceptibility (% S) of characterized MEM-NS isolates were observed. TGC remained active in vitro against > 92% of MEM-NS Enterobacteriaceae collected in EUR, LA, and NA and against >78% of isolates collected in MEA that carried a proportionately greater number of MBLs, and was more potent than other tested agents. TGC continues to display significant in vitro activity against difficult-to-treat Enterobacteriaceae.

    Krystyna Kazmierczak, PhD1, Meredith Hackel, PhD, MPH1, Brian Johnson, BS1, Dan Sahm, PhD1 and Heidi Leister-Tebbe, BSN2, (1)International Health Management Associates, Inc., Schaumburg, IL, (2)Pfizer, Inc., Collegeville, PA

    Disclosures:

    K. Kazmierczak, IHMA, Inc.: Independent Contractor , Consulting fee

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

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

    D. Sahm, 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.