Biofilms: A Phenotypic Mechanism of Bacteria Conferring Tolerance Against Stress and Antibiotics

Abstract

Biofilm, as a heterogenous congregation of microbial cells enclosed within a pellicle, has largely gained attention due to their historical importance in environment as sludges, flocs, slimes, etc. Biofilms in medical research have been an active area of research in periodontics, in wounds, and in surgical implants. With the availability of whole genome sequences, it is now evident that the mechanisms that control biofilm formation have largely remained conserved during the course of evolution, pointing to the fact that biofilm formation is an integral part in the lifecycle of any unicellular organism. The ability to easily inter-switch between planktonic to a sessile life cycle is an important armor for these unicellular organisms to overcome stress. The matrix not only acts a physical barrier that protects the bacteria but also provides an ecological niche for close interaction and communication among these unicellular entities. This coordinated community-like behavior synchronizes metabolic upregulation or downregulation, both in time and space, and allows these microorganisms to achieve physiological proficiency in terms of ability to tolerate stress that might not be possible as a single cell. Research on biofilms from the perspective to explore the mechanisms of drug tolerance is now considered an apt model as compared to the use of planktonic microorganisms. The increasing use of medical implants further necessitates the need to accelerate research in anti-biofilm strategies for these medical devices. This chapter presents an overview of the mechanisms of biofilm formation and the various interventions for prevention of biofilms.