IN VITRO EFFICACY OF CEFTAZIDIME-AVIBACTAM ON CARBAPENEM-RESISTANT PSEUDOMONAS AERUGINOSA ISOLATES

AHMET MANSUR, AYTEN GÜNDÜZ

Anatolian Journal of Pharmaceutical Sciences - 2025;4(1):48-52

 

Pseudomonas aeruginosa is the main Pseudomonas species causing hospital infections. Ceftazidime-avibactam (CZA) is a new beta-lactam/beta-lactamase inhibitor combination effective against carbapenem-resistant P. aeruginosa isolates. The aim of this study was to evaluate the in vitro activity of CZA against carbapenem-resistant P. aeruginosa isolates. In hospitalized patient culture samples, 190 isolates that were evaluated as significant growth and identified as P. aeruginosa with the Vitek 2 Compact automated system (BioMérieux, France) and determined as imipenem resistant (≥ 8 mg/L) and meropenem resistant (≥ 16 mg/L)with the same system were included in the study. 88% (167/190) of P. aeruginosa strains were isolated from patients in intensive care units and 78% (148/190) from respiratory tract samples. CZA activity was studied with disk diffusion test (10-4 µg disk) and zone diameters <17 mm were accepted as resistant. 20% (38/190) of the isolates were found to be resistant to CZA. The difference in resistance rates between CZA and all of the studied antimicrobials except amikacin is highly significant (p: 0.006 - <0.001). The low resistance rate found in our study indicates that CZA is a good option for the treatment of carbapenem-resistant P. aeruginosa isolates. In addition, amikacin treatment with a low resistance rate may be an appropriate approach for patients requiring combination therapy. The increasing problem of carbapenem resistance and multidrug resistance requires more studies to evaluate the effectiveness of new antimicrobials and drug combinations.