New Weapon Against MRSA

One of the most alarming health threats to emerge in the last decade has been the emergence of MRSA - methicillin-resistant Staphylococcus aureus, a potentially life-threatening infection that most frequently is contracted in what would seem like the most unlikely place - the hospital. A new weapon to strike at MRSA has been found by a multi-institutional team of researchers.

"We have found that the same golden armor used by Staph to thwart our immune system can also be its Achilles' heel," said Dr. Victor Nizet, a study co-author, who is affiliated with the Skaggs School of Pharmacy and Pharmaceutical Sciences at University of California-San Diego.

The magic bullet was found after a researcher specializing in infectious diseases at the University of Illinois' department of chemistry read of Nizet's work with squalene synthase receptor blockers - a family of drugs that are used to control the production of cholesterol in humans.

"I thought there was a good chance that squalene synthase inhibitors developed early on as cholesterol lowering agents might also work on this other pathway," said Eric Oldfield of Illinois. Oldfield recognized that many of the precursors for S. aureus' "golden armor" were the same as those with the synthase blockers. S. aureus gets its name from the color of a protein that encapsulates the bacteria - and gives it its edge against the human immune system.

The compound that creates the golden color of S. aureus is a caretonoid, and seems to help the bacteria hide from the body's white blood cells, allowing a colony of bacteria to grow until a massive infection has taken hold. Staph is the leading cause of human infections in the skin, soft tissues, bones, joints and bloodstream, and drug-resistant strains are a growing health threat.

By blocking a key enzyme in the pathway for the bacteria's production of the carotenoid compound, the virulence of the Staph may be brought under control. And since the compound used in the study, BPH-652, has already gone through clinical studies for cholesterol control, testing for its effectiveness with this new use should be able to be streamlined. A tiny dose of BPH-652 blocked the chemical pathway, and Staph went from golden in color to white - and wiped out their shield.

"This research is an excellent example of how discoveries at the lab bench can lead to clinical advances," said Dr. Elias A. Zerhouni, the director of the National Institutes of Health, which supported the research. "By following their scientific instinct about a basic biological process, the researchers found a promising new strategy that could help us control a very timely and medically important health concern."

The full study may be read at ScienceXpress.