Coexistence of Metallo Beta Lactamase Resistant Gene Variants Among Clinical Isolates in Tertiary Care Hospital

Abstract

Background: Carbapenem-resistant Enterobacteriaceae (CRE) has emerged as a global threat with mortality risk ranging from 48%-71% worldwide. The emergence of MBL resistance is threatening as carbapenem is one of the last line antibiotics. A total 24 variants of NDM resistance raises a concern to the clinicians and epidemiologists worldwide. Objective: The study aims at identifying MBL resistance (NDM, IMP, VIM, GIM, SPM, and SIM) and its coexistence in clinical isolates in a single tertiary care center. Methodology: Forty five clinical isolates characterized phenotypically for Carbapenem resistance obtained from PSG Institute of Medical Science and Research (PSG IMSR), Coimbatore, between February to March 2018 were taken for analysis. Result: Out of the 45 Clinical isolates, 38 isolates (84%) were detected as MBL carriers. VIM, NDM, GIM, and SPM were the predominant resistance genes, with detection rates of 48.8%, 28.8%, 24.4%, and 22.2% respectively. Fifteen isolates were observed to harbor more than one MBL gene in coexistence. Two isolates - U42 and R714 (K. pneumoniae) were found to harbor all 5 MBL variants in combination. Conclusion: 33% of clinical isolates harboring multiple MBL variants is a concern in clinical settings. The presence of SPM and GIM gene amongst isolates in this geographical location within India is an indicator demanding continuous monitoring of these resistance determinants.