Prevalence of Carbapenem Resistant Gram Negative Bacilli Harboring blaNDM-1 Gene Isolated in a Tertiary Care Hospital

Background: Increase in antimicrobial resistance is of major concern worldwide. This is largely attributed to broad spectrum $-lactamase production. New Delhi Metallo $-lactamase-1 (NDM-1) is a recently identified type of metallo-$-lactamase which has been increasingly viewed as a potential threat to global health. Objective: The aim of this study was to perform molecular detection of bla NDM-1 gene to determine its occurrence among clinical isolates of Gram negative bacteria. Methodology: A total of 178 Gram negative bacilli isolated from different clinical samples including urine, tissue, sputum, blood, pus, endotracheal secretion (ET secretion), stool, pleural fluid, cup tip, Peripherally Inserted Central Catheter (PICC) tip, drain tube and bile were included in the study. The isolates were identified by Vitek 2 GN cards and antibiotic susceptibility testing was performed by using Vitek 2 AST-N280 and AST-N281 cards (bioMerieux, SA, France), as per manufacturers instructions. The isolates were stocked and used for further study. PCR to detect the presence of bla NDM-1 gene was performed with all the isolates. The ERIC-PCR was performed with 17 bla NDM-1 positive representative isolates. Of the 178 isolates, a remarkably high incidence of 29.8% bla NDM-1 gene was found. Of the 53 bla NDM-1 positive cases, 17 representative isolates were studied for clonal relatedness by ERIC-PCR. Results: It was found that Klebsiella pneumoniae and Acinetobacter baumannii had 2 and 1 clonally related clusters, respectively. Pseudomonas aeruginosa and Escherichia coli were clonally divergent. We suggest that the genotypic detection of NDM-1 along with routine antimicrobial susceptibility test should be performed in all health centers worldwide. The bla NDM-1 gene has "An alarming potential" to spread and diversify among bacterial populations. Conclusion: Hence early identification of cases of NDM-related infections and prevention of their spread by implementing screening, hygiene measures and the isolation of carriers is required.