WASHINGTON — Drug-resistant staph bacteria picked up in ordinary community settings are increasingly acquiring "superbug" powers and causing far more serious illnesses than they have in the past, doctors reported.

These widespread germs used to be easier to treat than the dangerous forms of staph found in hospitals and nursing homes.

"Until recently we rarely thought of it as a problem among healthy people in the community," said Dr. Rachel Gorwitz of the federal Centers for Disease Control and Prevention.

Now, the germs are causing outbreaks in schools, on sports teams and in other social situations are posing a growing threat. A CDC study found that at least 10 percent of cases involving the most common community strain were able to evade the antibiotics typically used to treat them.

"They're becoming more resistant and they're coming into the hospitals," where they swap gene components with other bacteria and grow even more dangerous, said Dr. Keith Klugman, an infectious disease expert at Emory University. "It's really a major epidemic."

The germ is methicillin-resistant Staphylococcus aureus, or MRSA. People can carry it on their skin or in their noses with no symptoms and still infect others.

MRSA mostly causes skin infections. Cleveland Browns tight end Kellen Winslow was just hospitalized for a staph infection, his second in recent years, and the team reportedly has had at least six cases in the past three years.

But the germ can be life-threatening if it gets into the bloodstream, lungs or organs.

Pneumonia, sinus infections and even "flesh-eating" wounds due to MRSA are on the rise, doctors reported Monday at an infectious diseases conference in Washington.

About 95,000 serious infections and 20,000 deaths due to drug-resistant staph bacteria occur in the United States each year.