Fig. 2
From: Acinetobacter baumannii biofilm and its potential therapeutic targets
Diagram depicting the various processes of antibiotic resistance in biofilm ecosystems. Biofilm cells are adhered to the biotic or abiotic surface. In the stress zone where the nutrient and oxygen availabilities are low, the persister cells and less active deep layer cells develop. The figure depicts the following resistance: Antibiotic penetration is slowed by matrix of exopolysaccharides (EPS); extracellular DNA (eDNA); multidrug efflux pumps; outer membrane protein; antibiotic degrading enzymes; target alterations; drug neutralization; quorum sensing; and stress responses (SOS response and stringent response (SR))