Frequency of Ceftazidime-Avibactam Susceptibility In Specimens of Carbapenem-Resistant Pseudomonas Aeruginosa In A Tertiary Care Hospital

Objective: To determine the frequency of Ceftazidime-Avibactam (CAZ-AVI) susceptibility in specimens of Carbapenem-resistant Pseudomonas aeruginosa (CRPA) at a tertiary care hospital. Study Design: Analytical cross-sectional study. Place and Duration of Study: Department of Microbiology, Combined Military Hospital (CMH), Multan, Pakistan, from Jan-Jun 2024. Methodology: Specimens of carbapenem-resistant Pseudomonas aeruginosa were included in the study to find the susceptibility of CAZ-AVI using the standard Kirby Bauer disc diffusion method. Zones were interpreted using a Vernier caliper following Clinical Standard Institute (CLSI) 2023, where zone of CAZ-AVI ≥21 was considered as susceptible. Results: The total sample size was 103 CRPA specimens, out of which, 47(45.60%) were found to be susceptible to CAZ-AVI with an average zone of inhibition of 16.9 ± 8.8 mm, with male patients showing more susceptibility as compared to females (51.00% vs. 40.40%). The majority 44(68.80%) of resistant cases were from inpatient department as compared to the outpatient department 12(30.80%) (p-value <0.001). Organisms were more susceptible in the specimens bronchioalveolar lavage sputum (87.50% and 75.00% respectively) whereas the most resistant isolates were found in Tracheal aspirate and blood specimens (100.00%) (p-value <0.001). Conclusion: The study demonstrates that approximately 45.60% of carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates at a tertiary care hospital are susceptible to Ceftazidime-Avibactam (CAZ-AVI), supporting its potential role as a valuable treatment option.