"Then we tested the most promising compound against the next enzyme in the pathway, and we found that it was 20 times more active against that enzyme," Oldfield said.
That enzyme, called UPPS, "is important because it's involved in bacterial cell wall biosynthesis," he said. "And a lot of the antibiotics that we have drugs like penicillin, methicillin, vancomycin all target bacterial cell wall biosynthesis."
Graduate student Wei Zhu and research scientist Yonghui Zhang worked with Oldfield to develop and test new analogs of the compound that worked against UPPS.
"And we found one that was about 1,000 times more active than the first hit we had against FPPS," Oldfield said.
Illinois chemistry and Institute for Genomic Biology professor Douglas Mitchell tested the new compound against regular and drug-resistant S. aureus in cell culture and found that it had potent activity against both.
"He also found that it augmented the effects of methicillin" in methicillin-resistant Staph strains, Oldfield said.
In a final test, Dr. Victor Nizet at UC San Diego used the new compound to treat mice infected with MRSA.
"Twenty out of 20 animals survived if they were treated with this drug lead and zero survived if they weren't treated," Oldfield said.
More years of study will be needed to determine whether this compound or others like it will be effective in humans, Oldfield said, but the findings may allow scientists to target multiple enzymes essential to bacterial survival, thus reducing the likelihood that new forms of drug resistance will eme
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign