The rationale behind the use of high-dose sulbactam against CRAB infections. (a) Conventional-dose therapy with sulbactam may not be effective against CRAB, as this molecule can be hydrolysed by class A, ADC-type class C, OXA-type class D β-lactamases, and MBLs, which can be produced by CRAB isolates. As a result, sulbactam molecules cannot reach their targets, i.e. PBP1a, PBP1b and PBP3. (b) High-dose, extended-infusion therapy allows more sulbactam molecules to reach their PBP targets, as they overcome the hydrolysis by β-lactamases. Binding to PBPs leads to interruption of bacterial cell wall formation and consequently, to bacterial death. Figure created with BioRender.com.