9.2.1 Carbapenemases in non-Enterobacterales

In non-Enterobacterales such as Acinetobacter, carbapenem resistance is due to a variety of carbapenemases with a range of porins and drug efflux pumps (Hsu et al., 2017). In Pseudomonas resistance is frequently due only to increased efflux or porin loss without a carbapenemase being present. However, carbapenemases are found increasingly in Pseudomonas and as it is hard to discriminate the mechanism in practice; the organism may need to be sent to the reference laboratory if it is important to be sure of the mechanism.