Antimicrobial Resistance and Susceptibility Patterns of Clinical Pseudomonas aeruginosa Isolates from a Tertiary Care Hospital in Lahore, Pakistan

Abstract

Pseudomonas aeruginosa is a leading opportunistic pathogen in hospital settings and is increasingly associated with multidrug resistance (MDR), which narrows therapeutic options and worsens patient outcomes. Local surveillance data from tertiary care settings in Pakistan remain limited. This study aimed to determine the frequency of MDR P. aeruginosa among clinical isolates and to characterize their antibiotic susceptibility profile. We conducted a cross-sectional study over three months (March–May 2021) in the microbiology laboratory of a tertiary care hospital in Lahore. A total of 53 non-duplicate clinical specimens yielding P. aeruginosa were included. We identified isolates by standard morphological and biochemical methods. Antimicrobial susceptibility was determined by the Kirby–Bauer disc-diffusion method on Mueller–Hinton agar against eight antibiotics, with each assay performed in triplicate. Of the 53 isolates, 22 (41.5%) were multidrug-resistant. The cohort comprised 33 males (62.3%) and 20 females (37.7%), with most isolates recovered from patients aged 31–50 years. Resistance was highest to cefepime (45.3%) and lowest to amikacin and meropenem (30.2% each). Amikacin and meropenem were the most effective agents (69.8% susceptibility each), followed by imipenem (67.9%). Cefepime was the least effective agent tested. A high burden of MDR P. aeruginosa (41.5%) was observed. Aminoglycosides (amikacin) and carbapenems (meropenem, imipenem) retained the greatest activity and represent the most reliable empirical options in this setting, whereas cefepime should be used with caution. Continued antimicrobial stewardship and periodic local surveillance are warranted.