Pseudomonas aeruginosa: Evaluation of Pathogen Burden and Drug-Resistance Trends in a Tertiary Care Hospital.

Objective: To evaluate the pathogen burden and antibiotic-resistance trends of Pseudomonas aeruginosa among hospitalised patients at a tertiary care hospital.

Study Design: Retrospective, hospital record-based, cross-sectional study.

Place And Duration Of Study: Microbiology Laboratory, Allama Iqbal Medical College/Jinnah Hospital, Lahore, from January 2014 to December 2016.

Methodology: A total of 5,960 samples were collected from clinically suspected cases of bacterial infections, admitted to the hospital. Microbial identification and antibiotic susceptibility pattern were carried out and analysed.

Results: Out of a total of 5,960 samples, Pseudomonas aeruginosa was isolated from 1,268 (21.2%) specimens. Department-wise isolation rate was n=600 (42.9%), n=268 (15.4%), n=201 (12.6%), and n=199 (16.0%) from intensive care unit (ICU), surgical units, medical units, and Gynae wards, respectively (p<0.0001). Sample-wise isolation rate was, wound swabs n=448 (35%), urine n=356 (28%), sputum n=187 (14 %), tracheal aspirate n=127 (10%), blood n=99 (7%), and broncho-alveolar lavage n=51 (4%) (p<0.0001). Drug-resistance pattern showed low rates for carbapenems(meropenem n=440 (35%), Imipenem n=436 (34%) and beta-lactam + beta-lactamase inhibitor combination (piperacillin+tazobactam n=437 (34%) while alarming rates were observed for cephalosporins (ceftazidime n=716 (56%), fluoroquinolones (ciprofloxacin n=690 (54%), cefoperazone+sulbactam n=685 (54%), aminoglycosides (gentamicin, n=669 (53%), amikacin n=608 (48%), and monobactams (aztreonam n=666 (52%). Decreasing trend was observed only for amikacin 63% to 37%, aztreonam showed similar pattern throughout, while there was an increasing trend of drug resistance in all groups of antibiotics.

Conclusion: Emerging drug-resistant strains of Pseudomonas aeruginosa are probably linked to the injudicious use of antibiotics, leading to ineffective empirical therapy. Therefore, we suggest that culture and antimicrobial susceptibility testing should be done for targeted antimicrobial therapy against Pseudomonas aeruginosa.