Prevalence of Carbapenem-Resistant Enterobacteriaceae and the Genes Responsible for Carbapenemase Production in a Tertiary Care Hospital in South India

Abstract

Introduction: Carbapenem resistance in Gram-negative bacilli (GNB) is a major concern in the management of resistant infections. The mechanism of carbapenem resistance is most commonly mediated by carbapenemases. The five most common genes (NDM, KPC, VIM, OXA, and IMP) are responsible for carbapenemase production. Knowledge of these genes is important for the management of the disease. Objective: To estimate the prevalence of different genes responsible for carbapenemase production in GNB at a tertiary healthcare centre in South India. Method: In this retrospective study, samples were collected over 16 months. Carbapenem-resistant GNB underwent to Xpert Carba-R assay (Cepheid, Sunnyvale, California, USA) for the detection of five important genes responsible for carbapenemase production: NDM, KPC, VIM, OXA, and IMP. Results: Out of 184 carbapenem-resistant GNB, 20 samples were not included in this study. The rest of the 164 samples grew Klebsiella pneumoniae (152), Escherichia coli (10), and Enterobacter (2). OXA-48 and NDM were the most common genes responsible, with 137 (84.5%) and 95 (58.6%), respectively. Among them, 70 (43.2%) showed the presence of both genes, and 1 (0.6%) showed the presence of OXA-48, NDM, and VIM. Individually, 66 (40.7%) of OXA-48, 24 (14.8%) of NDM, and one (0.6%) of VIM. In this study, the authors did not find the presence of IMP or KPC genes. Conclusion: As a result of limited options and the higher cost of antibiotics for carbapenem-resistant infections, knowledge of these genes helps in the selection and rational use of antibiotics reduces the cost of management and will prevent mortality and morbidity from these infections.