New approach may render disease-causing staph harmless

University of Illinois chemistry professor Eric Oldfield realized that the chemical precursors of the Staph carotenoid were identical to those that led to production of cholesterol in humans. "I thought... Click here for more information.

Researchers at the University of Illinois helped lead a collaborative effort to uncover a completely new treatment strategy for serious Staphylococcus aureus (“Staph”) infections. The research, published Feb. 14 in ScienceXpress, the online version of Science magazine, comes at a time when strains of antibiotic-resistant Staph (known as MRSA, for methicillin-resistant S. aureus) are spreading in epidemic proportions in hospital and community settings.

Among the deadliest of all disease-causing organisms, Staph is the leading cause of human infections in the skin, soft tissues, bones, joints and bloodstream, and drug-resistant Staph infections are a growing threat. By federal estimates, more than 94,000 people develop serious MRSA infections and about 19,000 people die from MRSA in the U.S. every year. MRSA is believed to cause more deaths in the U.S. than HIV/AIDS.

The multi-institutional team exploited a chemical pathway that allows the Staph bacterium to defend itself against an immune response. The researchers showed that a compound (BPH-652) originally designed to lower cholesterol blocks a key enzyme in that pathway, weakening the organism’s defenses and allowing the body’s immune cells to prevail against the infection.

A golden-colored pigment called a carotenoid gives the S. aureus bacterium its edge. “Aureus” is Latin for “golden.” The carotenoid acts as an antioxidant for the bacterium, allowing it to evade attack by the body’s immune cells. By crippling production of the carotenoid, the compound strips Staph of one of its key defenses.

The new research builds on a recent discovery by scientists at the University of California, San Diego. The UCSD team, led by Dr. Victor Nizet, a professor of pediatrics and pharmacy, showed that knocking out a gene for an enzyme in the chemical pathway that produced the Staph carotenoid reduced its virulence.