Evaluation of the In vitro efficacy of ceftazidime-avibactam against Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa isolates from respiratory tract cultures in intensive care units

Authors : Emine Serap Yılmaz, Hacer Özlem Kalaycı

Pages : 80-84

Doi:10.32322/jhsm.1583801

View : 25 | Download : 76

Publication Date : 2025-01-12

Article Type : Research Paper

Abstract :Aims: Worldwide, an increase in multidrug resistance is observed in Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) isolates, leading to challenges in the treatment of infections caused by these pathogens. This study aims to investigate the in vitro efficacy of ceftazidime-avibactam (CZA) against isolates containing K. pneumoniae, E. coli, and P. aeruginosa strains obtained from respiratory tract samples sent from intensive care units. Methods: A retrospective analysis was conducted on 653 Enterobacterales (E. coli, K. pneumoniae) and P. aeruginosa isolates obtained from respiratory tract cultures, including sputum, tracheal aspirates, and bronchial lavage, from patients over 18 years old admitted to the intensive care units of Ordu University Training and Research Hospital between May 1, 2021, and May 1, 2024. Automated systems were used to identify the pathogens and perform antibiotic susceptibility testing. Discriptive data analysis was conducted using SPSS version 24.0. Results: A total of 653 isolates from respiratory tract samples were included in the study, consisting of 368 Enterobacteriaceae [61 E. coli (9.3%) and 307 K. pneumoniae (47%)] and 285 P. aeruginosa (43.7%). These samples were isolated from endotracheal aspirate (69.5%), sputum (27.9%), and bronchoalveolar lavage (2.6%). Among all isolates, 364 (55.7%) were found to be sensitive to carbapenems, while 289 (44.3%) were carbapenem-resistant. Of the samples, 631 (96.6%) were sensitive to CZA, while 22 (3.4%) were resistant. Although resistance to CZA was detected in 3.6% of K. pneumoniae isolates and 3.9% of P. aeruginosa isolates, no resistance was detected in E. coli. Colistin resistance was observed in 15.3% of K. pneumoniae and 5.6% of P. aeruginosa isolates, but was absent in E. coli isolates. Resistance rates to other antibiotics were as follows for E. coli, K. pneumoniae, and P. aeruginosa isolates, respectively: amikacin (3.3%, 46.6%, 8.1%), ciprofloxacin (73.8%, 73.6%, 85.9%), ceftazidime (67.2%, 77.8%, 35.8%), piperacillin-tazobactam (26.2%, 70%, 37.2%), and trimethoprim-sulfamethoxazole (52.5%, 66.4%, 0%). Conclusion: In our study, CZA was found to be the most effective antibiotic against multidrug-resistant Enterobacterales and P. aeruginosa isolates, followed by colistin.
Keywords : Çoklu ilaç direnci, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, seftazidim-avibaktam