Most infections outside hospitals are from a single, robust form, study says WASHINGTON - One single strain of bacteria is causing most cases of drug-resistant Staphylococcus aureus found outside hospitals in the United States, U.S. researchers reported on Tuesday.The USA300 strain of methicillin-resistant Staphylococcus aureus or MRSA is extraordinarily contagious and robust, the U.S. government researchers said.
