Sunday, October 7, 2018

Researchers discover how fatal biofilms form

fatal biofilms
biofilms 

Researchers discover how fatal biofilms form

What is a fatal or bacterial biofilm?

Biofilm is a collective of one or more types of microorganisms that can grow on many different surfaces. Each of these surfaces has a common defining feature: they are wet. Biofilms can be made on surfaces that are living or non-living and can be dispersed in natural, industrial and hospital settings. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single-cells that may float or swim in a liquid medium. 

Biofilms can be made on the teeth of most animals as a dental plaque, where they can cause tooth decay and gum disease. Biofilm bacteria can share nutrients and thus shelter from the harmful factors in the environment such as drying, antibiotics, and the body's immune system of a host. The microorganisms that make biofilms include bacteria, fungus, and protists.  By severely curtailing the effects of antibiotics, the formation of organized communities of bacterial cells can be deadly during surgeries and in urinary tract infections.  Adherent cells are embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances. 

Cells within the biofilm produce EPS components, which are usually polymer groups of extracellular polysaccharides, lipids, proteins, and DNA.  Because they have a three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes. Biofilms are growing on minerals and metals. They are found underground and above the ground. They can grow on animal tissues and plant tissues. Since protective shell can prevent potential treatment, biofilms are at their most dangerous when they invade human cells or form on sutures and catheters used in surgeries. Biofilms are the most dangerous when they attack human cells or are made on the suture and catheter used in surgery.

How Biofilms are Formed?

some scientists investigated how these biofilms develop, and potentially how to stop them. Finally, they found that biofilms form when bacterial cells gather and develop structures that bond them in a gooey substance. This gum can save cells from the outer world and allows them to make complex semi-organisms. Microbes making biofilms are shown to achieve specific mechanisms. Biofilm formation is a highly complex process, in which microorganism cells transform from planktonic to a sessile mode of growth. It has also been suggested that biofilm formation is dependent on the expression of specific genes which guides the establishment of biofilm. 

The process of biofilm formation is through a series of early events leading to adaptation under various nutrition and environmental conditions. This is a multi-step process in which there are some changes in the micro-organisms after adhering to the surface. During biofilm formation, many species of bacteria are able to communicate with one another through the specific mechanism called quorum sensing. It is a system of stimulation to coordinate various gene expression. Bacterial biofilm is less accessible to antibiotics and human immune system and thus poses a big threat to public health because of its involvement in the variety of infectious diseases. Biofilm formation has the following important steps (a) attachment initially to a surface (b) formation of micro-colony (c) three-dimensional structure formation (d) biofilm formation, maturation, and detachment.

The researchers found in their study, the bacterial colonies would grow to the point where they would be squeezed by either the walls of the chamber, the fibers, or the gel. They designed and built microfluidic devices and novel gels that housed uropathogenic E. Coli cells, which often cause urinary tract infections.
These devices have copied the environment inside human cells that host invasive bacteria during infection. Fighting biofilms has been particularly difficult because it has not been well understood how bacteria cells make the transition from behaving individually to existing in collective structures. This self-reliant stress was a trigger for the bio-construction itself. However, the researchers have found a key mechanism for biofilm formation that also provides a way to study this process in a controlled and reproducible way.

Andre Levchenko, the John C. Malone Professor of Biomedical Engineering and director of the Yale Systems Biology Institute, said in a statement “Biofilm is a huge medical problem because it is something that makes bacterial infections very difficult to deal with. It was astonishing, but we looked at everything you would expect from a biofilm. Cells produced biofilm components and suddenly became very antibiotic resistant. And all this was with an indication that the cells were under biological stress and the mechanical interaction with the environment was tense”. 

With this discovery, researchers can use various devices that mimic other cellular environments and explore biofilm formation in countless environments and circumstances. They can also use tools introduced in this study to produce a faster, accurate, and high numbers in a simple, affordable and reproducible way. This will allow screening drugs which can potentially violate the protective layer of biofilms and break it. One such type of disease model is important when you want to use these types of drug-screening. Now we can develop biofilms in a completely approximate way in specific shapes and specific places. A greater understanding of bacterial biofilm is required for the development of novel, effective control strategies thus resulting in an improvement in patient management.
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