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How Worried Should We Be About the 'Nightmare Bacteria' Making Headlines?

Don't panic...yet.
A culture of the E. coli bacteria with the mcr-1 gene. Image: Jon Thompson/Walter Reed Army Institute of Research

Late last week, news broke that may have put a damper on your long weekend barbecue: A drug-resistant "nightmare bacteria" had been found in the US for the first time.

When a headline has the word "nightmare" in it, it's natural to be a little, uh, concerned. But how worried do you need to be about the new discovery—and is there anything you can do about it?

First, let's recap the news. On Thursday, scientists from the Walter Reed Army Institute of Research (WRAIR) published a report in the journal Antimicrobial Agents and Chemotherapy that revealed they had identified the first known US case of a bacterial infection with a particular gene that provides resistance to colistin—a "last resort" antibiotic.


Despite the hair-raising headlines, it's not that one super bacteria resistant to all antibiotics has arrived in the US and now threatens to infect and kill you. In fact, the E. Coli infection identified was still susceptible to other kinds of antibiotics, and there have been cases in the US of bacteria resistant to colistin in the past. What's notable this time is that the researchers found bacteria that had mcr-1: a gene discovered in China last year that allows bacteria to be resistant to colistin and is easily passed from one strain of bacteria to another.

"It's not that this bacteria is highly transmissible," said Dr. Emil Lesho, director of WRAIR's Multidrug-resistant Organism Repository and Surveillance Network and co-author of the report. "The concern is that this gene confers resistance to one of the drugs we use as last resort because it's the last remaining thing available to kill a type of bacteria on the rise: carbapenem-resistant Enterobacteriaceae, or CRE."

CREs are resistant to a class of antibiotics called carbapenems, and often if you get a CRE infection, the only remaining option for treatment is colistin. That's why this new finding is so alarming: If CRE bacteria comes into contact with mcr-1 bacteria, they could easily trade off resistance and form a superbug. But don't freak out just yet.

"We want to make sure people are concerned about the problem of antibiotic resistance in general, but we don't want to create panic," Lesho told me over the phone.

In fact, there are a lot of reasons to breathe a sigh of relief. For one, the mcr-1 gene hasn't been detected in CRE bacteria yet. For another, even if it was, it could still possibly be treated through combining antibiotics or through other "last resort" antibiotics like tigecycline, which is rarely used because it's very harsh, only available intravenously, and usually causes nausea, vomiting, and diarrhea.

There's more hope in the fact that the US government is closely monitoring for these kind of bugs (which is how this case was detected), which can help prevent an outbreak from spreading. This, combined with the fact that we don't use colistin regularly, should help the mcr-1 gene from rapidly spreading. Researchers are also dedicated to finding other, non-antibiotic treatments, from phage therapy to bacteria-specific drugs that can knock out superbugs in other ways.

So should you just shrug it off? Not quite. Antibiotic resistance is a serious issue that, if left unchecked, could plunge us into a medieval time where every scraped knee and paper cut has the potential to turn deadly. Here's what the paper's authors said you can do about it: cook your meat thoroughly, wash your hands properly, and finish all of your antibiotics when you need them. I'd also add: consider the track record of the politicians you vote for this fall, as they're the ones who will get to make systematic changes that will determine how we fight antibiotic resistance going forward.