Selecting an antimicrobial regimen for carbapenem-resistant gram-negative infections is almost always challenging.

Understanding of the mechanism of resistance, carbapenemase producers (KPC, IMP, VIM, NDM, OXA-48, OXA-23/24 like) and non-carbapenemase producers (carbapenem resistance due to efflux pump and porin loss) has important clinical implications and results in individualized antibiotic therapy.

New beta-lactamase combinations have been made available within the last few years, and early results suggest they are safer and more efficacious for the treatment of CRE infections compared with some of the older agents, particularly polymyxin regimens.

The available treatment options for carbapenem resistant gram-negative pathogens (based on the specific mechanism of carbapenem resistance) are summarized in Table.