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lifestyle has undergone a paradigm shift.
The most essential feature required for development of biofilms, is the need for bacterial cells to attach themselves on to a surface that can help it propagate its sedentary life. Formation of biofilm involves attracting more number of cells to form an assemblage and extend themselves inside an externally secreted slimy substance called exopolysaccharide (EPS). EPS forms the skeletal framework that encompasses the channels to circulate nutrients and water. Attachment to a surface is followed by, an unalterable change in their gene expression, protein profiles and also certain physiological factors. These matured micro-colonies act in a different way, when compared to the individual cells. They tend to become resistant to harsh conditions, chemicals, and also, drugs. Cells in biofilm form a network and also articulate features different from their individual free
living counterparts. It is found
that, bacteria when they attempt
to establish in a particular
environmental niche, or cause
disease in a host, essentially
need to attain a specific cell
number. In order to increase the
cell numbers, there are various
signal mechanisms propagated
to initiate the population rise.
The means by which the
bacterial cells communicate
with the surrounding cells and
aggregate at a particular place
is scientifically regarded as
“quorum sensing”. The quorum-
sensing signals generated by the bacteria in a population are responsible for many characteristic features that are required to develop and broadcast biofilm bacteria. These systems heighten performance of pathogens in causing serious incidences in the disease. It is often found that the disease-causing bacteria
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that are capable of forming biofilms have supplementary infection causing ability and can result in recalcitrant infections. Secretion of EPS and progress of drug-resistance mechanism make the antibiotics impermeable as well as less effective.
As part of the doctoral research, developing an effective antibiofilm agent has been intended as one of the primary objectives. It has been reported that a number of natural and chemical compounds have been screenedthatshowedreductioninthebiofilm development, but accomplishment of absolute suppression has not been reported until now. Because of the complexity in the biofilms, it is essential to disrupt them by targeting multiple factors including cell death. However, with the advent of nanoparticles as a latest antimicrobial substance, our lab has initiated a process of developing an ideal antibiofilm agent inclusive of nanomaterials. Due to
their enhanced killing effect on microbial cells in smaller concentration, nanoparticles are already in use in various applications. But to use nanoparticles as an antibiofilm agent, they need to be further refined in their properties as well as enhanced in their ability to penetrate the protective layer of EPS. Even though research has not advanced to establish the precise role of nanoparticles as antibiofilm agent, their potent antimicrobial activity is well established. Furthermore,
certain facts endorsed by size and properties of nanoparticles can be assumed as a future prospective for using them to make an antibiofilm agent. Nanoparticles have enhanced penetration into the biofilm matrix and are also known to disrupt the cell membrane properties in microbes. In addition, unlike antibiotics
Usually, prolonged use of an antibiotic becomes ineffective against a particular bacterial species due to development of “drug resistance”. Bacteria develop resistance to an antibiotic by inactivating either the active component of the drug, or by modifying, the target site in the bacterial system.