Prevalence of carbapenemase-producing organisms in a tertiary care hospital in Ludhiana

Aim: This study was done to determine the minimum inhibitory concentration (MIC) of imipenem for multidrug-resistant (MDR) clinical isolates and identify carbapenemase-producing organisms among these MDR isolates. Materials and Methods: The antibiotic susceptibility of clinical isolates was determined by Kirby–Bauer disc diffusion method. MDR isolates showing resistance or reduced susceptibility to carbapenems were further tested for MIC with imipenem and carbapenemase production by Modified Hodge test (MHT). Results: A total of 65 MDR isolates were tested, of which 46 (70.77%), 15 (23%), and 4 (6.15%) had MIC in resistant, sensitive, and intermediate range, respectively. MHT was positive for 37 (57%) isolates. The most common carbapenemase producers in order of frequency were Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter aerogenes, Escherichia coli, Pseudomonas spp. Conclusion: Phenotypic tests such as MHT are simple, cost-effective, and easy to perform and hence can be used in any microbiology laboratory to detect carbapenemase production and applied clinically to guide the antimicrobial therapy, especially in severe and life-threatening infections