Bacterial biofilm development as a multicellular adaptation: antibiotic resistance and new therapeutic strategies.

Bacteria have evolved the ability to form multicellular, surface-adherent communities called biofilms that allow survival in hostile environments. In clinical settings, bacteria are exposed to various sources of stress, including antibiotics, nutrient limitation, anaerobiosis, heat shock, etc., which in turn trigger adaptive responses in bacterial cells. The combination of this and other defense mechanisms results in the formation of highly (adaptively) resistant multicellular structures that are recalcitrant to host immune clearance mechanisms and very difficult to eradicate with the currently available antimicrobial agents, which are generally developed for the eradication of free-swimming (planktonic) bacteria. However, novel strategies that specifically target the biofilm mode of growth have been recently described, thus providing the basis for future anti-biofilm therapy.