Microbial biofilms and their control by various antimicrobial strategies

In nature, bacteria as opposed to the planktonic form predominantly exist as biofilms. Biofilms are consortium of microorganisms and can be considered as complex communities of microorganisms which are embedded in a selfproduced matrix of extracellular polymeric substances attached to a substratum which can be inert or living surfaces. In the recent years, there is an increasing interest in studying biofilms. This is mainly due to the reason that biofilms are known to cause persistent and chronic infections. They are also a major problem in industries and food processing units. Their resistance to biocides, disinfectants and host immune responses makes their study important. In this review, the development and dynamics in microbial biofilms and the strategies employed to effectively control biofilms in industrial and medical settings as well as food processing units will be discussed in detail. The various environmental cues, genetics and molecular mechanisms involved in biofilm formation will be assessed in the review. The role of cell to cell communication or quorum sensing in biofilm formation and the use of anti-quorum sensing strategies in biofilm control will also be focused. The mechanism of action of various antibiofilm strategies including the use of phytochemicals, nanoparticles, quorum sensing inhibitors, enzymes and other novel biological approaches will be reviewed. The techniques used in studying biofilms will be briefly discussed.