Review on biofilm formation and its control options

Abstract

The generalized idea that bacteria have a unicellular way of life is not entirely accurate, given that pure planktonic growth is uncommon. Biofilms are defined as an organized group of microorganisms living within a self-produced matrix of polymeric substances which gets attached to several surfaces. This review was done with the objective to give an overview on the mechanism of biofilm formation and highlight its veterinary and public health implications and control options. The formation of a biofilm occurs in five stages, stage of cell attachment, stage securely affixing of cells, stage of micro-colonies formation and beginning to mature, Stage of more maturation, and stage of dispersal of cells from the biofilm. Factors controlling cell attachment include nature of surface, properties of medium and properties of the microbial cell surface. Formation of a biofilm is dependent on the interaction between the environmental stimuli and the reciprocation of the corresponding signalling events by the microorganisms. Biofilms are composed primarily of microbial cells and EPS. The importance of biofilm in disease processes in humans and animals is now widely recognized. In animal species, the risk of infection is probably greater than the risk in humans. In human infections associated with biofilm formation were medical device-related infections including Pacemakers, electrical dialysers, joint prosthetics, intravenous catheters, urinary catheter. As food is identified to be a very efficient vehicle for bringing a large number of people into contact with a potential hazard, food processing equipments can be persistent source of spoilage and pathogenic bacteria if microorganisms form biofilm on them. Ideally, preventing biofilm formation would be a more logical option than treating it. The main strategy to prevent biofilm formation is to clean and disinfect regularly before bacteria attach firmly to surfaces. This process can remove 90% or more of microorganisms associated with the surface. Biofilm detectors, acid shock treatment and recently using bacteriophages have been tried. The prevention and control of biofilm formation is somewhat difficult but prevention is the ideal approach even if there are control methods too. The development of better control and prevention methods with better effect need to be given special emphasis.