In:
European Journal of Clinical Microbiology & Infectious Diseases, Springer Science and Business Media LLC
Abstract:
Relebactam is a novel β-lactamase inhibitor, which, when combined with imipenem/cilastatin, is active against both class A and class C β-lactamases. To evaluate in vitro antimicrobial activity of imipenem/relebactam against a collection of recent clinical isolates of carbapenem-non-susceptible P. aeruginosa and K. pneumoniae ST258 and ST512 KPC producers belonging to different lineages from hospitals in Southern Spain. Methods Six hundred and seventy-eight isolates were tested: 265 K. pneumoniae (230 ST512/KPC-3 and 35 ST258/KPC-3) and 413 carbapenem-non-susceptible P. aeruginosa . Imipenem, piperacillin/tazobactam, ceftazidime, cefepime, aztreonam, ceftolozane/tazobactam, meropenem, amikacin, ciprofloxacin, colistin, and ceftazidime/avibactam were used as comparators against P. aeruginosa . Against K. pneumoniae ceftazidime, cefepime, aztreonam, and ceftolozane/tazobactam were not tested, and tigecycline was studied instead. MICs were determined in duplicate by broth microdilution according to EUCAST guidelines. Results Imipenem/relebactam displayed potent in vitro activity against both sequence types of KPC-3-producing K. pneumoniae . MIC 50 and MIC 90 values were 0.25 mg/L and 1 mg/L, respectively, with percent of susceptible isolates 〉 97%. Only three K. pneumoniae ST512/KPC-3 isolates and one ST258/KPC-3 were resistant to imipenem/relebactam. Relebactam sensitized 98.5% of K. pneumoniae isolates resistant to imipenem. The activity of imipenem/relebactam against P. aeruginosa was moderate (susceptibility rate: 62.7%). Analysis of the acquired and mutational resistome of isolates with high levels of resistance to imipenem/relebactam has not shown a clear association between them. Conclusion Imipenem/relebactam showed excellent activity against K. pneumoniae KPC-3. The activity of imipenem/relebactam against imipenem-resistant P. aeruginosa was moderate.
Type of Medium:
Online Resource
ISSN:
0934-9723
,
1435-4373
DOI:
10.1007/s10096-023-04735-1
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2023
detail.hit.zdb_id:
1459049-9
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