Abstract :
Background: Pseudomonas aeruginosa is an opportunistic pathogen and one of the leading causes of hospital-acquired infections due to its intrinsic and acquired resistance to multiple classes of antimicrobials. The emergence of multidrug-resistant (MDR) and carbapenemase-producing strains has posed significant challenges to infection control and patient management worldwide.Objectives: This study aimed to determine the prevalence, antimicrobial resistance pattern, and molecular detection of resistance genes in P. aeruginosa isolated from clinical samples at a tertiary care centre in Chennai.Materials and Methods: A cross-sectional study was conducted over six months (February–July 2021) in the Department of Microbiology, ACS Medical College and Hospital. Ninety-eight non-repetitive P. aeruginosa isolates from various clinical samples were identified using standard microbiological methods. Antimicrobial susceptibility testing was performed by Kirby–Bauer disc diffusion according to CLSI guidelines. Phenotypic screening and confirmatory tests for ESBL and carbapenemase production were carried out. Genotypic detection of resistance genes (blaTEM and blaNDM) was done using multiplex PCR.Results: Among 98 isolates, 52% were multidrug resistant. High sensitivity was noted for meropenem (83.7%) and piperacillin-tazobactam (79.6%), whereas aztreonam showed the highest resistance (54.1%). Phenotypic ESBL confirmation was negative, and blaTEM gene was not detected. Carbapenem resistance was observed in 28.5% isolates; of these, 28.6% harbored blaNDM genes. All carbapenem-resistant isolates were metallo-?-lactamase producers and retained 100% sensitivity to colistin.Conclusion: The study highlights the high burden of MDR P. aeruginosa and the emergence of blaNDM-positive strains. Routine surveillance, strict antibiotic stewardship, and infection control measures are crucial to prevent further spread.
Keyword :
Multidrug resistance, Pseudomonas aeruginosa, Carbapenemase, blaNDM