Biofilm - The Real Danger

Biofim are bacterial communities that can appear almost anywhere, fouling machinery, clogging pipes, and

contributing to many forms of human disease.

Researchers have found that biofilms play an important role in many medical conditions such as kidney stones, chronic ear and urinary-tract infections and gum disease. Experts at the Centre for Disease Control in Atlanta in the USA now believe that biofilms are involved in 65% of all human bacterial infections. And roughly 5% of patients who annually receive catheters and stents develop serious infections from biofilms growing on the devices.

Biofilms can also be found in water filters, on the hulls of boats and in drinking water pipes, where they can do great harm.

Worldwide, industry spend about $7bn on toxic chemicals that are only partially successful in blocking this bacterial scum.

At the earliest stages, this strange thing called a biofilm is little more than a layer of cells attached to a surface. But as the bacteria grow and divide, something wondrously conspiratorial happens. When enough of them - a quorum - have gathered, they send signals around, telling each other to reorganize. They begin to arrange themselves into an array of pillars and mushroom shaped structures, all connected by convoluted channels that deliver food and remove waste. They become in effect a community, with its own defence and communication systems. As the biofilm matures, the bacteria become as much as 1,000 times more resistant to antibiotics and biocides than they were when they were separate. So once a biofilm takes hold, getting rid of it is tough, though not impossible - thanks to GeoSIL.

Traditionally, it has been believed that dosing water services with a conventional biocide such as chlorine will keep free of harmful and possibly life threatening bacteria & viruses. Unfortunately, this is simply not true!

Bacteria can penetrate many systems and are often introduced by tiny insects which are very more adept at gaining entry. These bacteria, once in the system are not easily dislodged. Once inside the system the bacteria gravitate towards the surfaces of the water tanks and pipes, where nutrient levels of adsorbed organic molecules are their richest. Owing to their small size, the bacteria could very easily be swept away in the water flowing through the system. To prevent this happening, they secrete a polysaccharide glue like substance that fixes them to the surfaces and enables them to pick out nutrients carried along in the water. This polysaccharide matrix is what makes up the biofilm - surrounding each bacterium in layers of slime and creating a miniature "Static pond" for it, safe from disruptive water currents.

The biofilm also acts as a barrier to biocides like chlorine, which react with its surface layers while letting the protected bacteria population grow unchecked, until they break out of the biofilm to cause disease and infection, such as an outbreak of Legionnaires disease. Fortunately, there is an answer to the problem created by biofilm. That answer is GeoSIL.

GeoSIL solutions will penetrate biofilm and destroy the bacteria on contact.

The necessity of using powerful biocides for biofilm removal is illustrated in recent work which demonstrated that it took four times as much bromide to destroy bacteria in biofilm as it took to destroy bacteria in water flow. GeoSIL can bring down bacteria levels to single figures, and more particularly is very effective against Legionella which can exist in systems even when the TVC water condition is well within accepted standards,

GeoSIL's effectiveness against Legionella in both hot and cold systems has enabled building services managers to provide safe water, even in systems which have difficulty in maintaining the 60oC level recommended. Dosing the system with GeoSIL can also prevent the pipe corrosion caused by the co-existence of two quite different types of bacteria in the biofilm. The upper layers of biofilm are populated by aerobic bacteria, and the lower layers (Lacking in oxygen) by anaerobic bacteria. This co-existence creates a corrosion potential between the oxidising and reducing bacteria, resulting in the removal of pipe metal by natural electrolysis. Biofilm develops faster in plastic pipes than in metal pipes, as the biofilm will find nutrients in the organic content of the pipe.

Apart from its effectiveness in penetrating biofilm and killing the actual bacteria, GeoSIL solutions have a long residual level of disinfection. It is less reactive than other biocides such as Chlorine or Ozone which stay in the water for a significantly shorter period of time. By using solutions of GeoSIL, protective levels of biocide can be maintained in water systems for 14 days or more and so provide protection during "Shut downs". The need to flush out systems or carry out chlorinations prior to reopening can be eliminated.