Antibacterial drivers of resistance.

Increased levels of antibacterial resistance among community-acquired pathogens have been influenced by various factors. Among the antibacterial-related drivers of resistance, the inappropriate and excessive use of antibacterials has been identified. A large number of antibacterial prescriptions can be attributed to syndromes of viral etiology; given that antibacterials provide no clinical benefit, this represents an important target for decreasing unnecessary antibacterial use. Notably, therapeutic exposure of bacteria to antibacterials exerts a continuous selection pressure on pathogens as well as on normal flora. This selection pressure may favor and/or enable resistance development through various mechanisms. The development of resistance may be reduced by avoiding subtherapeutic antibacterial exposure and prolonged treatment durations. Potency, or the product of in vitro antibacterial activity and the ability of an antibacterial to achieve adequate concentrations at the site of infection, is also a critical consideration. In general, the more potent an antibacterial, the less likely it is to propagate resistant isolates. Antibacterial resistance is unavoidable. However, consideration of the drivers of resistance and concerted efforts to avoid these effects will help to better control the development of resistance.