This discovery could be the first step toward human intervention in these signaling pathways, a phenomenon known as quorum sensing, either by thwarting activities of harmful bacteria or facilitating activities of helpful ones. The work is reported by researchers at Cornell University, Argonne National Laboratory and Monsanto Co. in the latest edition of the journal Nature (June 27, 2002).
"There are many examples of bacterial processes that are effective only when carried out by large numbers of bacteria acting in a coordinated fashion, and coordination of behavior requires a communication system," explains Stephen C. Winans, professor of microbiology at Cornell. "One example of coordinated behavior is the formation of biofilms, which are mats of immobile bacterial cells stuck to a solid surface. Biofilms are ubiquitous in nature and can be harmful in some cases and beneficial in others. A deeper understanding of signaling could improve our ability to intervene in these and other processes."
He notes that one kind of bacterial biofilm smothers the lungs of cystic fibrosis victims. Knowing the configuration of an essential quorum-sensing protein might permit structure-based design of a drug to block the chemical signal before bacteria join in a drug-resistant biofilm. Conversely, the rapid formation of useful biofilms, such as biofilters to clean water or biobarriers to contain contamination, might be encouraged now that biologists know, in precise structural detail, what the quorum-sensing signal needs to proceed.
Molecular census-taking also is thought to occur in more than 70 other types of microorganisms, including bioluminescent bacteria, which tog
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