Functional Diversity of Gram-Negative Permeability Barriers Reflected in Antibacterial Activities and Intracellular Accumulation of Antibiotics

Abstract

Gram-negative bacteria are notoriously more resistant to antibiotics than Gram-positive bacteria, primarily due to the presence of the outer membrane and a plethora of active efflux pumps. However, the potency of antibiotics also varies dramatically between different Gram-negative pathogens, suggesting major mechanistic differences in how antibiotics penetrate permeability barriers.