Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 2 2025 04 05 253 260 Nargis Bali Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu & Kashmir, India Tufail Ahmed Department of Microbiology, Govt Medical College, Anantnag, Jammu & Kashmir, India Biswajyoti Borkakoty Viral Research and Diagnostic Laboratory, Regional ICMR Laboratory, Dibrugarh Assam, India Roseleen Bali Department of Respiratory and Pulmonary Medicine Apollo Hospital, New Delhi, India Anjum Mir Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu & Kashmir, India Zubair Teli Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu & Kashmir, India Qounser Nisar Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu & Kashmir, India Tantray Faisal Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Soura, Jammu & Kashmir, India 2024 07 25 2025 01 30 Background and Objectives: We assessed the susceptibility of ceftazidime+avibactam (CZA/AVI) in Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from intensive care units of our hospital. Materials and Methods: Clinical samples from Jan 2022 to Dec 2023 at SKIMS Soura, were processed for the recovery of K. pneumoniae and P. aeruginosa. Susceptibility testing was done by disc diffusion (DD) method and minimum inhibitory concentration (MIC) for CZA/AVI and meropenem was assessed using E-test strips. Categorical agreement (CA), very major errors (VME), major errors (ME) and minor errors (mE) between DD and MIC were measured. Statistical analyses were performed using SPSS version 22.0. Results: A total of 111 K. pneumoniae and 81 P. aeruginosa were part of the study. Of these, 56.8% K. pneumoniae and 45.7% P. aeruginosa isolates were susceptible to CZA/AVI. MIC of CZA/AVI for K. pneumoniae ranged from 0.125 to ≥ 256 μg/ml and for P. aeruginosa it ranged from 0.032 to 128 μg/ml. CA was 97.29% between DD and E-Test for CZA/AVI in K. pneumoniae isolates, with a ME of 2.70%. For P. aeruginosa CA between DD and E-Test for CZA/AVI was 98.76% with a VME of 1.23%. MIC values of meropenem were higher than CZA/AVI even in sensitive isolates. Conclusion: CZA/AVI shows good in-vitro activity against clinical isolates of K. pneumoniae and P. aeruginosa and can be part of empirical therapy for treating infections caused by these bacteria. https://ijm.tums.ac.ir/index.php/ijm/article/view/4940 https://ijm.tums.ac.ir/index.php/ijm/article/download/4940/1764