The present invention provides compositions and methods for sensitizing a bacterium to an antibacterial the method comprising the step of exposing the bacterium, in the presence of an entry-promoting agent, to an agent that inhibits antibacterial resistance. Methods for killing an antibacterial-resistant bacterium comprising the step of exposing the bacterium, in the presence of an entry-promoting agent, to an agent that inhibits antibacterial resistance and exposing the bacterium to an antibacterial are also provided. The methods may also include the step of identifying the bacterium and the antibacterial resistance profile of the bacterium and tailoring the methods accordingly. Exemplary entry promoting agents provided are polyhexamethylene biguanide (PHMB) and polyhexamethyleneguanide (PHMG). Exemplary agents that inhibit antibacterial resistance are agents that bindto and inhibit antibacterial-resistance determinants such as beta-lactamases, PBP2a, NDM-1 and Vim2. Compositions, pharmaceutical compositions/formulations and medical uses thereof are also provided according to the invention.
