A top U.S. health official said Tuesday that it’s likely more people will be found to be carrying a newly discovered superbug. The bacteria, found in the urine of a Pennsylvania woman, is resistant to antibiotics of last resort.
Beth Bell, a top expert on antibiotic resistance at the Centers for Disease Control and Prevention, also said officials investigating the Pennsylvania superbug case don’t know how the strain of E. coli wound up in the woman’s body. And they may never find out, she said.
The E. coli bacteria contained a gene, known as mcr-1, that makes it resistant to the antibiotic colistin, the drug used against particularly dangerous types of superbugs that can already withstand other antibiotics. In the short term, experts stress that there is no need to panic because the strain found in the woman is still treatable with other antibiotics. E. coli is common and is typically present in the human gut.
But the discovery has alarmed public health officials because it’s the first time this colistin-resistant gene has been found in an individual in the United States. Over the long term, experts are worried that colistin resistance, which can spread easily to other bacteria through this gene, could lead to superbugs that could cause untreatable infections.
“We don’t know a lot about this particular gene,” said Bell, director of the CDC’s National Center for Emerging and Zoonotic Infectious Diseases, during a telephone briefing with Pennsylvania state health department officials Tuesday. It’s possible the person acquired it from food or person-to-person transmission.
“It’s possible, in this particular situation, that we won’t ever find out,” she said.
But she said officials weren’t surprised that the resistant gene turned up in the United States. U.S. officials have been hunting for it since November, she said, after Chinese and British researchers reported finding the colistin-resistant strain in pigs and raw pork and in a small number of people in China. The superbug strain was later discovered in Europe and elsewhere.