Kolter, Greenberg, and others have shown that bacteria living in biofilms use different genes from those they employ as free-floating cells. These most likely include an array of genes that resist antibiotics and destroy enemies. The bugs that attack the lungs of cystic fibrosis patients, for example, make cyanide, presumably to kill off other bacteria and block colonization by other species. Most antibiotics have been developed to kill individual bacteria. Yet many chronic and recurring infections appear to be caused by drug-resistant biofilms.
Some physicians give kids antibiotics for six months or more to try to control the infection.
There may be new antibiotics for treating biofilm infections. But the best long-term strategy, Costerton contends, is to learn to play with bacteria's signals. The earliest studies on quorum sensing identified a signal-response language used by some marine bacteria. Over 30 species are now known to communicate using this same language. Bassler has demonstrated that many bacteria, including most human pathogens, also share a universal tongue, a bacterial Esperanto.