What are biofilms?
what biofilms are, and why you should care
Date: 12/18/2010 10:30:21 AM ( 30 mon ) ... viewed 4554 times
what exactly are biofilms?
The simplest explanation is that biofilms are a protective covering that bacteria and/or fungi are capable of creating. These organisms conglomerate together, and then attach to the body, very often the wall of the intestinal tract. Once they've got a stable colony started they produce what is called an extracellular matrix, which covers and protects the colony.
this protective matrix is extraordinarily strong. I it also poses an extremely difficult problem if the bacteria or fungus contained within the biofilm is pathogenic. Many biofilms are antibiotic resistant. let's say you have a very serious intestinal bacterial infection. Your doctor prescribes a powerful antibiotic. You take the drug and it successfully kills all of the pathogenic bacteria it comes into contact with. You feel much much better. You believe you are well. you finish the course of antibiotics and go back to your life. Suddenly, three weeks or six months later the exact same bacteria is once again wreaking havoc in your body. you are back to square zero.
How did this happen? One possible explanation is that the pathogenic bacteria had created a protective biofilm matrix and had hunkered down in there, safe from the anti-biotic and just biding its time to when it was safe to come back out again. Once the antibiotic had been cleared from your body, the bacteria eventually ventured out from under the protective covering of the biofilm, and started the slow process of repopulating and re-colonizing your intestinal track.
This may also explain why so many people come oh so very close to completely eradicating their candida albicans infections, but can never quite do it. It's very possible that candida is hiding underneath biofilms that cannot be penetrated by any of the substances the person took to kill off the candida.
Here is what Wikipedia has to say about biofilms
A biofilm is an aggregate of microorganisms in which cells adhere to each other and/or to a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance (EPS). Biofilm EPS, which is also referred to as slime (although not everything described as slime is a biofilm), is a polymeric conglomeration generally composed of extracellular DNA, proteins, and polysaccharides in various configurations. Biofilms may form on living or non-living surfaces, and represent a prevalent mode of microbial life 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.
Formation of a biofilm begins with the attachment of free-floating microorganisms to a surface. These first colonists adhere to the surface initially through weak, reversible adhesion via van der Waals forces. If the colonists are not immediately separated from the surface, they can anchor themselves more permanently using cell adhesion structures such as pili.
The first colonists facilitate the arrival of other cells by providing more diverse adhesion sites and beginning to build the matrix that holds the biofilm together. Some species are not able to attach to a surface on their own but are often able to anchor themselves to the matrix or directly to earlier colonists. It is during this colonization that the cells are able to communicate via quorum sensing using such products as AHL. Once colonization has begun, the biofilm grows through a combination of cell division and recruitment. The final stage of biofilm formation is known as development, and is the stage in which the biofilm is established and may only change in shape and size. The development of a biofilm may allow for an aggregate cell colony (or colonies) to be increasingly antibiotic resistant.
The biofilm is held together and protected by a matrix of excreted polymeric compounds called EPS. EPS is an abbreviation for either extracellular polymeric substance or exopolysaccharide. This matrix protects the cells within it and facilitates communication among them through biochemical signals. Some biofilms have been found to contain water channels that help distribute nutrients and signalling molecules. This matrix is strong enough that under certain conditions, biofilms can become fossilized.
Bacteria living in a biofilm usually have significantly different properties from free-floating bacteria of the same species, as the dense and protected environment of the film allows them to cooperate and interact in various ways. One benefit of this environment is increased resistance to detergents and antibiotics, as the dense extracellular matrix and the outer layer of cells protect the interior of the community. In some cases antibiotic resistance can be increased a thousandfold. Lateral gene transfer is greatly facilitated in biofilms and leads to a more stable biofilm structure.
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