Prevalence of Pseudomonas aeruginosa and Acinetobacter baumanni Isolated from Clinical Samples in a Tertiary Care Hospital Islamabad

Abstract

1. A. baumannii and P. aeruginosa are Gram-negative coccobacilli and important nosocomial pathogens in healthcare settings, causing significant morbidity and mortality worldwide. Both are intrinsically resistant to many drugs and have the ability to develop resistance to virtually all antimicrobial agents. This study was conducted to determine the prevalence of Pseudomonas aeruginosa and Acinetobacter baumannii isolated from various clinical samples. It was a three-year retrospective cross-sectional study. A total of 810 clinical specimens were evaluated using conventional methods for identification, and antimicrobial susceptibility was determined using the Kirby-Bauer disc-diffusion method. The isolates were obtained from suspected bloodstream infections, wound infections, urinary tract infections, and surgical site nosocomial infections. Sociodemographic and other variables of interest were collected using a structured checklist from patient record data. The data was analyzed using SPSS version 26, with a p-value of <0.05 considered statistically significant. A total of 810 clinical samples were evaluated from the years 2021 to 2023. Of these, 440 (54%) were males and 370 (46%) were females, with ages ranging from 1 to 90 and mean and median ages of 39.3 years and 37 years, respectively. Among the samples, A. baumannii accounted for 364 (60.6%) and P. aeruginosa accounted for 446 (39.4%). Blood was the main source of isolates (18%), followed by urine (16%) and CSF (10%). In the analysis, we found that P. aeruginosa had the highest prevalence in all three years, ranging from 38% to 29%. In conclusion, A. baumannii is an emerging pathogen with a wide range of resistances, making it difficult to control. Effective antibiotics include imipenem, meropenem, piperacillin/tazobactam, ciprofloxacin, gentamicin, tobramycin, colistin, and polymyxin B, while fluoroquinolones, aminoglycosides, cephalosporins, and carbapenems are used.