The main cause of death among cystic-fibrosis patients, and a threat to many burn victims and AIDS patients as well, is the bacterium Pseudomonas aeruginosa. But the microbe is not a health problem until enough of the bacteria join together to form a gooey amalgamation called a “biofilm.” Almost 80 percent of bacterial infections are in biofilm form. Helen Blackwell, an assistant professor of chemistry, studies quorum sensing – the communications mechanism that tells bacteria that they have replicated enough to form a biofilm. Its easy, according to Blackwell, to synthesize the organic molecules that bacteria use to talk to each other.
Blackwell is testing a series of such messenger molecules to see if she can hijack the bacterias communications network. So far, of the hundreds of molecules she has screened, 10 seem promising. The right molecule might fight a hard-to-treat infection or induce a small, early infection to stimulate the bodys immune response. Blackwells group developed a way to speed up the reaction that produces the messenger molecules by heating it with microwaves. “We reduce a reaction sequence from about three days to about 45 minutes,” she says.