IOWA CITY, Iowa -- The war against bacteria rages on, but a new battle plan has been drawn.
Bacteria existing together in a structure called biofilm are often more resistant to attack by antibiotics and the immune system than they are as individual cells.
This resistance presents a difficult problem for physicians, but recent research has revealed a way in which the biofilm fortress might be attacked. Dr. E.P. Greenberg, University of Iowa professor of microbiology and UI colleague, Matthew Parsek, together with investigators at Montana State University and the University of Rochester, have discovered a signal molecule released by bacteria called Pseudomonas aeruginosa that is essential for the development of biofilm. This finding is reported in the April 10 issue of the journal Science.
"This is basic research, but it leads us in two research directions," Greenberg says. "It may help us find a way to dislodge the biofilm, or it could lead to ways in which we could impair a biofilm, making it more sensitive to antibiotics."
Scientists are now learning that despite their reputation as rugged individualists, bacteria spend a considerable amount of time in communities. When a single, free-floating bacterium recognizes a surface, such as a rock in a stream or cell lining a blood vessel, it may attach to it. At first the bacterial cells multiply and spread across the surface, but when they reach a certain density, they build a complex biofilm structure with built in water tunnels to carry nutrition into the cells and carry the waste out. Scientists call this process differentiation. The message that initiates differentiation has puzzled researchers for some time.
Greenberg and his colleagues discovered the chemical message that Pseudomonas
aeruginosa uses to "tell" the community that it is time to build the biofilm
structure. Pseudomonas aeruginosa, the organism that can infect catheters or
medic
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Contact: L.E. Ohman
le-ohman@uiowa.edu
(319) 335-6660
University of Iowa
9-Apr-1998