Background: P. aeruginosa is a major nosocomial pathogen. This long-term surveillance study is to evaluate the frequency and antimicrobial susceptibility trends of P. aeruginosa over a 15-year period. Methods: We conducted a retrospective single center study of P. aeruginosa isolates using the VITEK 2 system between 2010 and 2024. Data was analyzed as frequency, ratio, and resistance trends. P. aeruginosa susceptibility was examined for the available antipseudomonal agents. Trends were assessed by Poisson Generalized Linear model, and visualized. Effect size was measured as rate ratio (RR), and P-value considered < 0.05 as significant. Results: A total of 1728 isolates were identified over the fifteen years, P. aeruginosa was 9.12% of gram-negative bacteria, ICU contributed to 12.9% of the isolates. There was a decreasing frequency trend (RR = 0.98, P < 0.000). Also, there was a reduction in resistance rates except levofloxacin (RR = 1.04, 95%C.I. 0.97 - 1.11, P = 0.30). Carbapenems were almost stationary (RR = 1.008, P ≥ 0.54). Carbapenems resistance P. aeruginosa rate was 40.7%, and the Extended Spectrum β-Lactamases producers (ESBL) was 6.7%. Conclusion: Resistant P. aeruginosa rates are high for carbapenems and fluoroquinolones with a concerning susceptibility and MIC distribution. Though, the current study demonstrated a marginal decreasing resistance trend for the other antimicrobials. The findings underscore the importance of continuous local surveillance to inform empirical therapy and reinforce antimicrobial stewardship strategies in resource-limited settings.
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