What is a Biofilm?

June 20, 2019
What is a Biofilm?

Though you may not be immediately familiar with the term biofilm, you have certainly encountered it in your daily life (probably a lot more often than you’d think!).

A biofilm is made up of colonies of one or more type of microorganism that form together under a sticky glue-like substance and attach to a variety of surfaces. Microorganisms such as bacteria, fungi, and protists commonly make up biofilm colonies.

The most common example of biofilm is dental plaque – yep, the slimy buildup of bacteria that forms on the surface of your teeth is actually one type of bacterial biofilm. Most people carry this type of biofilm inside their mouth unknowingly.

The unwanted gunk that clogs your shower and sink drains is another example, and that slippery coating that may have caused you to slip on the rocks in a stream, river, or pond is another type of biofilm.

Where is a Biofilm Found?

So, what defining feature is shared amongst the inside of your mouth, your drains, and a pond? Moisture.

Any environment that has a combination of moisture, nutrients, and a surface of any sort is likely to attract some type of biofilm.

Since a biofilm does not need much more than water to survive and create a strong colony, it is able to exist in almost every environment on Earth – from super hot springs to the inside of your body.

Biofilm can form on all kinds of surfaces, including natural materials above and below ground, underwater, plastics, metals, and even on implanted medical devices within the human body such as pacemakers and catheters.

Natural plant and body tissues are also common environments to find biofilm formations.

How is a Biofilm Formed?

A colony of biofilm can be formed with only a single bacterial species, but in natural settings, biofilms almost always consist of a variety of species that can include bacteria, algae, fungi, protozoa, yeasts, and debris substances.

For example, over 500 bacterial species have been identified in an individual sample of typical dental plague (bacterial biofilm).

Biofilm colonies form when groups of bacteria adhere to the same surface in moist environments by excreting a slimy, glue-like substance.

The formation process begins when free-floating microorganisms come into contact with a surface in an appropriate environment and begin to lay down roots, per se.

This first step – attachment (stage 1 in the image below) – occurs as the microorganisms produce the “glue” – a gooey substance known as extracellular polymeric substance (EPS). EPS is made up of sugars, proteins, and nucleic acids (DNA, for example) which come together to form the “glue” that enables the microorganisms in the biofilm to stick together.

How Biofilm is Formed

Following the initial attachment phase is a period of growth in which more and more layers of microorganisms and EPS build upon the existing layers (stage 2) to eventually create a complex and bulbous-like 3D structure on the surface (stage 3).

Environmental conditions such as the amount of oxygen and water flow will determine the extent to which the biofilm colony can grow (how many layers it will be made up of).

Clumps of microorganisms can break away from the colony together or individual cells will burst out to move on and seek a new surface to make their home. This final part of the formation process is known as “seeding dispersal” (stage 4).

How Does Biofilm Affect Humans?

Given the vast range of environments that biofilms can inhabit, it is no surprise that these colonies may have an effect on certain aspects of human life.

Let’s focus specifically on how biofilm can affect human health and wellbeing.

Bacterial and fungal biofilms have been found to implicate a variety of health complications, from minor infections to more serious conditions like pneumonia.

Biofilm can pose a rather serious threat to human health, as the strength of the bacteria becomes too much for regular antibiotics to fight off.

Biofilm are a real-life example of “strength in numbers”. As more and more bacteria join together to form a biofilm, they become stronger and more resistant to common antibiotics that are usually enough to fend off these same bacteria within the human body.

While we are more than capable of fighting off these bacteria individually, once they join together as biofilm there is no such drug that can match the force.

In fact, scientists estimate that a biofilm is up to 1,500 times more resistant to major disinfectants generally used to control the same bacteria in individual circumstances.

Biofilm is especially dangerous in healthcare facilities where it can come into contact with open wounds, disabling the infected area from healing properly.

Furthermore, biofilm can grow on implanted medical devices within the body such as prosthetic heart valves and joint prosthetics. This can lead to very serious infections.

Bacterial biofilms can also cause infective endocarditis and pneumonia, amongst other infections. The elderly, diabetics, and people with compromised immune systems are at a higher risk.

As scientists further their research into biofilm and recognize the strength of these colonies, they now estimate that 60-80% of bacteria that contributes to human illness actually exist as biofilm.

Ultra-Fresh Helps Prevent Biofilm

When Ultra-Fresh antimicrobial additives are added to products during the manufacturing step, they render the treated item inhospitable to bacteria, mold and in some cases, algae.

Since microorganisms are discouraged from settling on antimicrobial treated surfaces, attachment and biofilm formation are prevented.

Read more about what antimicrobial agents are and how to incorporate them into plastic and polymer products, coatings or textiles.

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