| Impact of Biofilms on Humans |
What is the impact of biofilms on humans? Most are benign, like the slippery coating on a rock in a stream, but others can cause serious problems. For example, biofilms contribute to corrosion in metal piping and can reduce the flow of fluids necessary for many industrial applications, including power generation. A particular concern is the contamination of medical devices such as urinary catheters, hemodialysis equipment, and medical and dental implants. Biofilms that develop on these devices can increase the risk of patient infection. The recognition that biofilm formation contributes to disease extends beyond the Pseudomonas infections suffered by cystic fibrosis patients. Tuberculosis, Legionnaire's disease, periodontal disease and some infections of the middle ear are just a few examples of diseases that involve the formation of biofilms. The Centers for Disease Control and Prevention estimates that biofilms account for two-thirds of the bacterial infections that physicians encounter.
Several strategies can be used for attacking biofilms. For example, one might interfere with the synthesis of the extracellular matrix that holds the film together. Scientists are investigating coating medical devices with chemicals that hinder matrix formation. Another strategy involves inhibiting the adherence of biofilm cells to their substrate. Identifying chemicals that bind to cell surfaces, stopping the formation biofilms before they begin, is also an ongoing interest of researchers. Targeting the molecules that biofilm bacteria use to communicate is a third tactic.
In 1995 Peter Steinberg of the University of New South Wales, Australia, realized that the fronds of a red algae growing in Botany Bay are rarely covered with biofilms. He determined that the algae produce substituted furanones, chemicals that resemble the acylated homoserine lactones necessary for bacterial communication. Evidently, the furanones bind to bacterial cells, thereby blocking the ability of the cells to receive the signals for quorum sensing. Although these compounds are too toxic for human use, similar compounds are being investigated for inhibiting the Pseudomonas biofilms that form in cystic fibrosis patients.