Controlling Bacteria Without Antibiotics

September 20, 2005

Most human and animal diseases are associated with bacteria that are assembled in “communities” called biofilms, which attach themselves to many surfaces, such as live tissues, implants, and teeth. Biofilms can also be found on nonbiological surfaces, such as water pipes or air-conditioning ducts.

Only recently has it been discovered that bacteria that accumulate in biofilms have a communications network between them called “quorum sensing,” which controls their collective activity. Sensing signals control the physiology and pathogenicity of the bacteria in the biofilms. A boron-based molecule that is produced by these bacteria, called auto inducer-2, controls the signals in this quorum-sensing process.

Jabbour has succeeded in synthesizing modified chemical compounds, resembling the structure of the natural auto inducer-2, which can disrupt the signaling. By altering the molecular structure in these compounds, Jabbour was able to show that one can control the quorum-sensing responses and “trick” the bacteria.

The modified compounds distort the signaling that sets off the bacterial changes, making it possible to hamper seriously the bacterial action or, if so desired, even enhance it (in those cases where the bacteria are beneficial).

Control over quorum sensing provides a promising avenue for future treatment of bacterial pathogenic activity, without having to resort to antibiotic drugs and their accompanying disadvantages. On the other hand, enhancing quorum sensing could prove useful in agriculture, biotechnology, and the food industry, where increasing bacterial activity could be beneficial.

Excerpted from an article by Judy Siegel-Itzkovich, Jerusalem Post For further information, please contact the Hebrew University head office, Mount Scopus, Jerusalem 91905, Israel; Tel: 972-2-658-5111; Web site: ww.huji.ac.il/huji/eng/

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