Abstract
Background: In recent decades, Pseudomonas aeruginosa has emerged as a multidrug-resistant bacteria by acquiring intrinsic resistance to a number of antimicrobial agents by uses distinctive resistant mechanisms to all the available antibiotics, which include metallo-β-lactamases (MBL) production, extended spectrum β-lactamase production, Amp C production, decreased permeability, altered penicillin binding proteins and rarely, and over expression of efflux pumps.

Aims and Objectives: The aim of the study was to know the presence of IMP gene among P. aeruginosa isolates and to determine the carbapenem resistance mechanisms in carbapenem-resistant isolates of P. aeruginosa collected from sputum, blood, urine, pus, in Chennai, India.

Materials and Methods: A total of 20 of non-repetitive clinical isolates of P. aeruginosa were collected and processed for biochemical tests and confirmed. Antibiotic susceptibility testing was determined by Kirby Bauer disc diffusion method. P. aeruginosa isolates were detected for the presence of blaIMP gene by polymerase chain reaction analysis.

Results: Of the 20 clinical isolates of P. aeruginosa, 9/20 (45%) isolates were from sputum, 5/20 (25%) from blood, 3/20 (15%) from urine, and 3/20 (15%) from pus. Only 2/20 (10%) isolates showed sensitivity to imipenem. Other than that, for all other antibiotics isolates showed complete resistance 20/20 (100%). 17/20 (85%) clinical isolate of P. aeruginosa was found to possess blaIMP gene.

Conclusion: The early detection of MBL‑producing P. aeruginosa may help in appropriate antimicrobial therapy and avoid the development and dissemination of these multidrug-resistant strains. However, to derive a conclusion, a more number of isolates are recommended and even other types of genes are also screened.

Key words: BlaIMP Gene; Pseudomonas aeruginosa; Polymerase Chain Reaction; Metallo-Beta-Lactamase