In vitro effect of aztreonam-avibactam and ceftazidime/avibactam-colistin combinations against carbapenem-resistant Pseudomonas aeruginosa strains isolated at Bach Mai Hospital
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Abstract
The minimum inhibitory concentrations (MICs) of aztreonam–avibactam (AZT-AVI) were determined for 204 carbapenem-resistant Pseudomonas aeruginosa isolates recovered from respiratory specimens at Bach Mai Hospital in 2025 using the broth microdilution method. Of these, 100 isolates were selected for assessment of the in vitro activity of the ceftazidime/avibactam (CZA)-colistin combination by the checkerboard method. The results showed that the MICs of aztreonam-avibactam against carbapenem-resistant P. aeruginosa ranged from 1 µg/ml to ≥ 32 µg/ml, with the MIC50 equaled to 16 µg/ml and the MIC90 at ≥ 32 µg/ml. For the ceftazidime/avibactam-colistin combination, all tested isolates (100%) exhibited an indifferent interaction. These findings were less favorable than anticipated, indicating that the selection of effective therapeutic options for multidrug-resistant P. aeruginosa remains a major clinical challenge and underscoring the need for further investigation of novel treatment strategies.
Article Details
Keywords
MIC, Pseudomonas aeruginosa, aztreonam-avibactam (AZT-AVI), ceftazidime/avibactam (CZA), colistin (CS)
References
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