TY - JOUR
T1 - In vitro activity of imipenem-relebactam and ceftolozane-tazobactam against resistant gram-negative bacilli
AU - Schmidt-Malan, Suzannah M.
AU - Mishra, Avisya J.
AU - Mushtaq, Ammara
AU - Brinkman, Cassandra L.
AU - Patela, Robin
N1 - Funding Information:
Research reported in this publication was supported by Merck & Co.
PY - 2018/8
Y1 - 2018/8
N2 - Understanding which antimicrobial agents are likely to be active against Gram-negative bacilli can guide selection of antimicrobials for empirical therapy as mechanistic rapid diagnostics are adopted. In this study, we determined the MICs of a novel -lactam–-lactamase inhibitor combination, imipenem-relebactam, along with ceftolozane-tazobactam, imipenem, ertapenem, meropenem, ceftriaxone, and cefepime, against 282 drug-resistant isolates of Gram-negative bacilli. For isolates harboring blaKPC (n 110), the addition of relebactam to imipenem lowered the MIC50/MIC90 from 16/ 128 g/ml for imipenem alone to 0.25/1 g/ml. For isolates harboring blaCTX-M (n 48), the MIC50/MIC90 of ceftolozane-tazobactam were 0.5/16 g/ml (83% susceptible). For isolates harboring blaCMY-2 (n 17), the MIC50/MIC90 of ceftolozane-tazobactam were 4/8 g/ml (47% susceptible). Imipenem-relebactam was active against most KPC-producing (but not NDM- or IMP-producing) Enterobacteriaceae and is an encouraging addition to the present antibiotic repertoire.
AB - Understanding which antimicrobial agents are likely to be active against Gram-negative bacilli can guide selection of antimicrobials for empirical therapy as mechanistic rapid diagnostics are adopted. In this study, we determined the MICs of a novel -lactam–-lactamase inhibitor combination, imipenem-relebactam, along with ceftolozane-tazobactam, imipenem, ertapenem, meropenem, ceftriaxone, and cefepime, against 282 drug-resistant isolates of Gram-negative bacilli. For isolates harboring blaKPC (n 110), the addition of relebactam to imipenem lowered the MIC50/MIC90 from 16/ 128 g/ml for imipenem alone to 0.25/1 g/ml. For isolates harboring blaCTX-M (n 48), the MIC50/MIC90 of ceftolozane-tazobactam were 0.5/16 g/ml (83% susceptible). For isolates harboring blaCMY-2 (n 17), the MIC50/MIC90 of ceftolozane-tazobactam were 4/8 g/ml (47% susceptible). Imipenem-relebactam was active against most KPC-producing (but not NDM- or IMP-producing) Enterobacteriaceae and is an encouraging addition to the present antibiotic repertoire.
KW - Antimicrobial resistance
KW - Gram-negative bacilli
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UR - http://www.scopus.com/inward/citedby.url?scp=85052017885&partnerID=8YFLogxK
U2 - 10.1128/AAC.00533-18
DO - 10.1128/AAC.00533-18
M3 - Article
C2 - 29760145
AN - SCOPUS:85052017885
VL - 62
JO - Antimicrobial Agents and Chemotherapy
JF - Antimicrobial Agents and Chemotherapy
SN - 0066-4804
IS - 8
M1 - e00533-18
ER -