Molecular characterization of extended-spectrum beta-lactamases and carbapenemases producing Enterobacteriaceae isolated from North Eastern region of India

Abstract

Objectives: This study is aimed to investigate the prevalence of genes encoding extended-spectrum β-lactamases (ESBLs) and carbapenemases production among Enterobacteriaceae isolated from North East India. Materials and Methods: A total of 210 non-duplicate multi-drug resistant Enterobacteriaceae (MDRE) strains were included in this investigation. The isolates were resistant to third-generation cephalosporins, aminoglycosides, and fluoroquinolones. First, the strains were subjected to phenotypic assays to determine ESBLs and carbapenemases production; then, multiplex polymerase chain reaction (mPCR) assays were done to detect ESBLs and carbapenemases genes. In addition, efflux pump activity was determined by phenylalanine-arginine b-naphthylamide assay. Statistical Analysis: The frequency of ESBLs and carbapenemase genes among MDRE strains was shown as percentages. The data analysis was done using Microsoft Excel computer software. Results: Among 210 MDRE clinical isolates, ESBLs production was observed in 72.86% (153) isolates. During mPCR assay, gene encoding ESBLs were detected in 55.24% (116) MDRE strains beta-lactamase Temoniera (blaTEM) (26.67%, 56), beta-lactamase Cefotaxime-Munich (blaCTX-M) (19.52%, 41), and beta-lactamase sulfhydryl reagent variable (blaSHV) (9.05%, 19)]. In addition, 55 (26.2%) and 53 (25.26%) strains were found to be meropenem and imipenem resistant, respectively. Carbapenemase nordmann-poirel (Carba-NP) test for carbapenemases activity was found to be positive in 18.58% (39) MDRE strains. The genes encoding carbapenemases production was observed in 18.58% (39) MDRE [beta-lactamase New Delhi metallo-β-lactamases-1(blaNDM-1) (8.10%, 17), beta-lactamase oxacillinase-48 (blaOXA-48) (2.86%, 6), beta-lactamase Verona imipenemase (blaVIM) (1.43%, 3), and blaOXA-48 and blaVIM (6.19%, 13)]. Efflux pump activity was observed in 5 (2.3%) of Carbapenem-resistant Enterobacteriaceae isolates. Conclusions: For the first time in this region, we have detected the presence of blaOXA-48 and blaVIM in a single MDRE isolate as high as 6.1%. Therefore, clinicians need to detect the ESBLs and carbapenemases producing Enterobacteriaceae on priority in hospital settings for therapeutic options as well as stringent infection control strategies to be adopted as precautions.