Blood Stream Infection Caused by Carbapenem-resistant Chryseobacterium indologenes Harboring blaNDM-1 Gene Isolated from a Tertiary Care Hospital in Tripura: An Emerging Threat

Abstract

Objectives: Chryseobacterium indologenes has recently been identified as an inherently drug-resistant organism, responsible for a wide spectrum of infections, mainly device-associated infections in hospital settings. The presence of carbapenem resistance due to blaNDM-1 metallo-β-lactamase (MBL) gene further complicates the matter, leading to widespread dissemination of carbapenem resistance. This study aims to find out the presence of blaNDM-1 gene among C. indologenes strains causing bloodstream infections in a tertiary care hospital. Materials and methods: During 1 year of the study period, blood culture samples were collected from patients with features of bacteremia, and C. indologenes strains were isolated and identified as per protocol. Antibiotic sensitivity test was performed by using VITEK 2 Compact Automated AST machine (Biomerieux, France). Carbapenem-resistant strains were subjected to a combined disk diffusion test for detecting the presence of MBL enzyme. Strains positive for MBL production were subjected to a polymerase chain reaction (PCR) for detection of blaNDM-1 gene. Results: Out of 21 strains isolated during the study period, 12 strains (57.1%) were carbapenem-resistant. Among them, seven strains (58.3%) were MBL producers. After PCR, 3 strains (42.9%) were found to be harboring blaNDM-1 gene. Discussion: As per our knowledge, this is the first report of blaNDM-1 gene harboring C. indologenes strain from Northeast India. This shows the emerging therapeutic dilemma due to the narrowing of treatment options against bloodstream infections due to C. indologenes strains. Strict antimicrobial stewardship has to be implemented to prevent the further compounding of the problem.