Evolving trends of New Delhi Metallo-betalactamse (NDM) variants: A threat to antimicrobial resistance.

The rapid emergence of carbapenemase producing Gram-negative bacterial strains exhibit broad-spectrum β-lactam resistance, especially New Delhi metallo-β-lactamase (NDM-1). It is a major public health threat as it catalyses the hydrolysis of a vast variety of β-lactam antibiotics, including carbapenems, which is the last choice for physicians to treat infections. NDM-1 and its variants are continuously spreading worldwide, in spite of constant efforts to control. Its clinical treatment remains challenging due to continuous evolution of new variants. A thorough structural study of all variants is required to develop new and effective inhibitors. This review focuses on the dissemination, position of substitution and carbapenemases activity of all the 28 NDM variants so far reported.