Prevalence and molecular characterization of carbapenem resistant gram-negative bacilli in a tertiary care hospital in Mumbai

Carbapenem (CR) among gram-negative bacteria is a worldwide problem. It is ranked in the highest priority category in the World Health Organization (WHO) global priority list of pathogens.It is responsible for therapeutic failure in both hospital and community-acquired infections. Identifying and monitoring the local epidemiology of the carbapenem resistant organisms, understanding specific mechanisms underlying the resistance and implementing measures to prevent their spread is the need of the hour. The aim of the study was to determine the prevalence and molecular epidemiology of Carbapenem resistant Gram negative bacilli in this hospital. : A retrospective study was carried out in the Department of Microbiology of a tertiary care Hospital in Mumbai from January to December 2022. All Gram negative bacilli from various specimens were identified and antimicrobial susceptibility was reported using the VITEK2 automated system (BioMerieux, Durham, North Carolina) and interpreted as per CLSI 2022 guidelines. The resistant genes in the isolates were detected by Xpert Carba-R assay (Cepheid, Sunnyvale, CA) on request by a consulting physician. : Out of 2,351 gram negative bacilli isolates, 624 were Carbapenem resistant (26.5%). (59.9%) was the most common CR isolate. Molecular testing was done for 190 of these 624 CR isolates. In which New Delhi Metallo beta lactamase (NDM (33.68%) was the most common resistant gene identified followed by NDM & OXA-48(32.63%). With the prevalence of Carbapenem resistant isolates in the settings, adherence to infection control practices and stringent implementation of antimicrobial stewardship is crucial to curb the rate of infection.