Identification and antimicrobial resistance in pseudomonas aeruginosa

Introduction: Pseudomonas aeruginosa is a gram negative bacterium that continues to be a major cause of opportunistic nosocomial infections, causing around 9-10% of hospital infections. It is hard to treat because of intrinsic resistance of the species and its resistance to multiple groups of antibiotics including β-lactams, aminoglycosides and fluoroquinolones. This study was undertaken to determine the prevalence of P. aeruginosa
and its susceptibility pattern isolated from pus samples.
Material and Methods: In this study a total of 57 P.aeruginosa isolates were obtained out of 254 pus samples between a period of one year(Feb 2015 to Jan 2016). The isolates were selected on the basis of their growth characteristics on Blood agar, MacConkey agar and Nutrient agar medium. Colonies were subjected to battery of biochemical tests to identify species. Antimicrobial susceptibility testing of all confirmed P. aeruginosa isolates was performed by Kirby –Bauer disc diffusion method and results were interpreted according to CLSIs guidelines.
Results: The prevalence of this pathogen was 22.4% and most of the isolates were found to be highly sensitive to Colistin (95.4%), Polymyxin B (95%), Levofloxacin (83.3%), Imipenam (70%), Netilmycin (66%) and Piperacillin+ Tazobactum (64.5%). However, they showed resistance towards Ofloxacin (65%), Piperacillin (64%), Ceftazidime (56.3%), Cefoprazone (58%), Cefpime (55%), Aztreonam (53%), Cefaprazone + sulbactum
(46%) and Gentamicin (45%). Fourteen (24%). P. aeruginosa isolates were Multidrug
resistant (MDR) as they were totally resistant to Cephalosporins, aminoglycosides, fluoroquinolones and carbapenems.
Conclusion: High prevalence of P. aeruginosa as an opportunistic pathogen has been on the increase with resistance to antimicrobial agents and thus becoming a threat.