Genetic diversity, biochemical properties, epidemiology, and detection methods of IMP- and VIM-type carbapenemases

SUMMARY Metallo-beta-lactamases are an ever-growing problem. Since the discovery of the beta-lactamase of Bacillus cereus in the late 1960s, many class B beta-lactamases have been reported, with three main families being NDM-, IMP-, and VIM-like. IMP- and VIM-like carbapenemases have been identified in a wide variety of Gram-negative bacteria. VIM-type carbapenemases are widely distributed, primarily represented by two main clusters, VIM-1 and VIM-2, and have been found in both Enterobacterales and non-fermenters. IMP-type carbapenemases are characterized by a significant genetic diversity and low identity between subgroups. This carbapenemase is more prevalent in Asia but has been identified globally, in both Enterobacterales and non-fermenters, as observed for VIM-type carbapenemases. The genetic diversity of IMP- and some VIM-type carbapenemases limits their detection. This review aims to discuss the genetic diversity, epidemiology, and biochemical characteristics of VIM- and IMP-type carbapenemases. It also evaluates the efficacy of commercially available detection tests and the in vitro activity of recently developed inhibitors.