In-vitro Activity of Ceftazidime-avibactam Against Multidrug-resistant Pseudomonas Aeruginosa: Cross-sectional Study from a Tertiary Care Hospital

Introduction: Multidrug-resistant (MDR) Pseudomonas aeruginosa poses a major therapeutic challenge in tertiary-care settings, necessitating local, Clinical and Laboratory Standards Institute (CLSI) -anchored susceptibility data for empiric therapy and stewardship. This study characterises Ceftazidime– Avibactam (CZA) activity and Minimum Inhibitory Concentration (MIC) distribution to support stewardship and local guideline updates Aim: To evaluate the in-vitro activity of CZA against MDR Pseudomonas aeruginosa clinical isolates from a tertiary care hospital in North India. Materials and Methods: This was a hospital-based, crosssectional study conducted in the Bacteriology Division, Postgraduate Department of Microbiology, Government Medical College, Srinagar, Jammu and Kashmir, India, from January 2022 to December 2022 and included 108 non duplicate MDR Pseudomonas aeruginosa clinical isolates. Standardised workflows encompassed specimen culture and identification, Kirby-Bauer disc diffusion, and ceftazidime-avibactam MIC determination by E-test interpreted per CLSI M100 (2022), while demographic parameters recorded for context included age group and gender. Susceptibility was reported as proportions, and predictors of CZA non susceptibility were estimated using multivariable logistic regression. A p-value of