By inserting a naturally occurring molecule into an antibiotic-resistant bacterium, the team was able to gradually destroy the machinery responsible for the resistance.

"Multidrug-resistant bacteria are now ubiquitous in both hospital settings and the larger community," wrote Paul J. Hergenrother, a professor of chemistry, in a paper that appeared online ahead of publication in the Journal of the American Chemical Society. "Clearly, new strategies and targets are needed to combat drug-resistant bacteria."

Antibiotic resistance makes it difficult to fight infection and increases the chance of acquiring one while in a hospital. That, in turn, has led to more deaths from infection, longer hospital stays and a greater use of more toxic and expensive drugs, according to the National Institutes of Health.

Resistance occurs when bacteria develop ways to make themselves impervious, such as by pumping antibiotics out of the cell, preventing them from entering the cell or demolishing them. A common way bacteria develop resistance is by laterally transferring plasmids -- pieces of extra-chromosomal DNA -- from one bacterium to another. These plasmids contain genetic codes for proteins that make bacteria insensitive to antibiotics.

"Our idea was that if you could eliminate plasmids that make the bacterium resistant, then the bacterium could be sensitive to antibiotics again," Hergenrother said.

The researchers' approach was to use a natural process called plasmid incompatibility. "If there is one plasmid in a cell and another one is introduced, then they compete with each other for resources," Hergenrother said. "One of them wins and the other is eliminated."

With the help of chemistry graduate students Johna C.B. DeNap, Jason R. Thomas and Dinty J. Mus
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Contact: Jim Barlow, Life Sciences Editor
jebarlow@uiuc.edu
217-333-5802
University of Illinois at Urbana-Champaign
12-Nov-2004