Researchers say they've figured out how the antibiotic-resistant staph infection beats the body's immune system.
In a report in the journal Nature Medicine, the research team says the aggressive strain of the so-called MRSA infection secretes a compound that causes germ-fighting cells to explode, eliminating a main defense against it. Experts say the findings may help lead to better treatments.
An estimated 90,000 people in the U.S. fall ill each year from MRSA infections. It's not clear how many die from them, but one estimate puts it at more than 18,000. That would be slightly higher than U.S. deaths from AIDS.
The infection long has been associated with health care facilities, where it attacks people with weakened immune systems. But it can cause severe infections and even death in otherwise healthy people outside of health care settings as well.