In a large and hostile world, a single, free-floating bacterium has little chance of survival. Faced with temperature fluctuations, deadly chemicals, and a sparse food supply, the odds are against the lone microbe. Fortunately for bacteria, though, there is a safe haven in their microscopic universe called biofilm. A biofilm is a group of colonized bacteria, usually found attached to a solid surface. The colonies form in a two-step process. Initially, bacteria known as the primary colonizers collect along a surface and begin excreting a gel-like polysaccharide substance. This substance creates a layer known as the biofilm matrix. The matrix then traps other bacteria, the secondary colonizers, and provides a nutrient-rich environment on which they thrive.1 One of the more common types of biofilm is unsightly dental plaque. The fact that plaque can only be removed by the rigorous scraping of a dental professional is a testament to the adhesive strength of the matrix.

Like most bacteria, those that form biofilms prefer a moist, stagnant environment. In addition to these requirements, the biofilm colonizers need a large, smooth surface on which to multiply. Unfortunately, these conditions are present in many man-made devices in which bacterial contamination is particularly problematic. Any system with narrow plastic tubing is an ideal environment for biofilm colonization. Dentistry equipment, endoscopes, soft-drink fountains, and ice-cream machines are just a few such devices in which biofilms create potential health hazards for patients and consumers. It is difficult to imagine how bacteria could manage to colonize in tubes where there exists a continuous passage of liquid. However, a principle of fluid dynamics known as laminar flow explains the phenomenon. When a viscous fluid passes through a cylindrical pipe, the velocity of the fluid is greatest at the center, and approaches zero along the walls of the cylinder. The zero-velocity (stagnant) fluid along the pipe's walls is ideal for biofilm formation and continued growth.

As biofilm accumulates along the walls of a tube, an increasing number of bacteria are swept into the flow of the fluid. In some untreated dental units, the bacteria count has been measured at levels far exceeding the levels prescribed by the federal drinking water standards. This is particularly disturbing, as this water is administered directly to patients, and dental practitioners are exposed as well. Although not all bacteria are harmful, several pathogens have been detected in biofilms, including nontuberculous mycobacteria, Pseudomonas aeruginosa, and Legionella pneumophila.2 These disease-causing microbes pose a serious risk to immuno-compromised patients like the elderly and those infected with HIV.

Biofilm is a truly incredible adaptation for the survival of bacteria. Its inherent structure renders typical anti-bacterial methods ineffective against the powerful matrix and the immune system does know how to deal with it. In addition, biofilm cannot be manually removed in the situations where its presence is most dangerous because of the tiny diameter of the tubing in which it resides. Biofilm resists chemical disinfection in two ways. First of all, the gel-like polysaccharide layer provides a physical barrier against any outside agent, biological or chemical.3 Secondly, even if a biocidal agent is introduced in high enough concentration to eliminate the living bacteria, the organic, non-living matrix remains. This matrix not only traps useful nutrients, but also retains cellular components which can easily be recycled by new colonizers.4 The biofilm matrix is essentially a fully furnished home complete with a stocked refrigerator and an open door! A few bacteria need only to stumble across this matrix and rapid re-colonization is virtually guaranteed, rendering the disinfection useless.

Simple. Instead of trying to kill the bacteria or filter the fluid, Novaflux gets to the root of the problem by eliminating the biofilm and its matrix. Chemicals and filters cannot do this, and therefore leave the real problem intact. Novaflux's patented dual-phase technology quickly and safely blasts the biofilm lining, breaking it up and rinsing it away.

LITERATURE CITED: 1.) A Biofilm Tutorial. http://instruct1.cit.cornell.edu/Courses/biomi290/Horror/Biof.tutorial.HTML. Accessed: 6/21/99. 2.) Barbeau, J., Gauthier, C., Payment, P. 1998. Biofilms, infectious agents, and dental unit waterlines: a review. Canadian Journal of Microbiology. 11:1019-1028. Abstract. 3.) Costerton, J. W., Cheng, K.-J., Geesey, G. G., Ladd, T. I., Nickel, J. C., Dasgupta, M., Marrie, T. J. 1987. Bacterial biofilms in nature and disease. Ann. Rev. Microbiol. 41:435-64. 4.) Ibid.

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