AUDIE CORNISH, HOST:
Public health experts have been tracking a particular germ closely because it's resistant to antibiotics. Now for the first time, it's appeared in the U.S. It was found in a Pennsylvania woman with a urinary tract infection. NPR health correspondent Rob Stein joins us now to explain why doctors are so worried about this. And, Rob, start by telling us what's so concerning about this particular germ.
ROB STEIN, BYLINE: Well, Audie, this germ first showed up in China last year. And since then, it's popped up in a bunch of other countries in Europe and other parts of the world. And this germ carries a gene known as MCR-1. And the reason that's important is this gene makes any germs that have it resistant to an antibiotic known as colistin. And colistin is the antibiotic doctors use when no other antibiotic works - when they've tried everything else and none of them work. And it's sort of a antibiotic last resort. So any infections, any germs that have it basically can't be treated by the only antibiotic left that's available.
CORNISH: What's known about the woman who contracted it?
STEIN: Yeah, so the woman who contracted it - she's a 49-year-old woman who went to a clinic, as you mentioned, in Pennsylvania to get treated for a urinary tract infection. And her doctor sent specimens of the bacteria that were causing the infection to the Walter Reed Army Institute of Research, which is outside Washington. They analyzed it and discovered that it had this gene - this MCR-1 gene. And it turned out that in her case the bacteria were still susceptible to other antibiotics, so they were able to treat her. And she's - I'm told she's fine.
CORNISH: OK, she's fine. So help us understand why doctors are so concerned.
STEIN: Well, the worry is that her infection was caused by an E. coli bacteria. And, you know, that's a pretty - very common bacteria that causes all kinds of infections. And this gene - this MCR-1 gene that I mentioned - it can jump from one germ to another really easily. So the worry is that it could jump to other kinds - other E. coli strains or other germs. And there are other strains out there that are resistant to every other antibiotic. And so if this gene jumps into one of those, doctors won't be able to use colistin, and they'll have no way to treat patients who have these infections.
CORNISH: All right, so that's the concern for doctors. What about the rest of us? How worried should we be about this news?
STEIN: Well, you know, I'm told that public officials - I talked to folks at the CDC - the Centers for Disease Control and Prevention - today and elsewhere, and they are taking this very seriously. They said this is a significant development and - but there's no reason to freak out because it doesn't pose any immediate widescale public health threat. But they are taking steps to try to investigate it and to contain it, basically.
CORNISH: Can you talk about what else public health authorities are doing now?
STEIN: Yeah, so the CDC is working with health officials in Pennsylvania to try to answer a bunch of questions. A big one is - where did it come from? How did this woman get this? From all initial reports, she didn't travel outside the country, so did she catch it from somebody else? And that's really important, so they're going interview family members, acquaintances, with the idea of trying to figure where it came from so they can contain it and try to keep it from spreading widely if they can.
CORNISH: And at the end of the day, the concern here is about this bigger issue of antibiotic resistance, right?
STEIN: Yeah, absolutely. You know, public health folks have been kind of becoming increasingly concerned about antibiotic resistance, which has been increasingly significant in recent years. And, you know, we all grew up in a world where, you know, if we got an infection, for the most part, we go to our doctor, they'd give us an antibiotic, and we'd be fine. But more and more germs are becoming resistant to more and more antibiotics, to the point where there are - in parts of the world, there are germs that can't be treated with anything. And so the worry is we could get to the point where officials start to refer to as a post-antibiotic world where basically what were routine infections that were no big deal - there's no way to treat them, and people start dying from them.
CORNISH: That's NPR's Rob Stein. Rob, thank you.
STEIN: Oh, sure. Thank you. Transcript provided by NPR, Copyright NPR.