A germ that can't be treated with an antibiotic that is often used as the last resort has shown up for the first time in the United States.
Government scientists say the case is cause for serious concern but doesn't pose any immediate public health threat.
The germ was discovered in a 49-year-old woman in Pennsylvania with a urinary tract infection. The infection was caused by E. coli bacteria that had a gene that made them resistant to an antibiotic known as colistin.
The findings were published online Thursday in Antimicrobial Agents and Chemotherapy.
Colistin, a medicine that dates to the 1950s, is now used on infections that have become resistant to every other antibiotic. In this case, the woman's infection could still be treated with another antibiotic. She recovered.
But the case is still causing concern among public health officials. Now that this resistance gene has shown up in the U.S., it could spread to other germs, creating infections that doctors will have no way to treat.
That's already happened in other parts of the world, including China.