In “Tracking a Hospital Outbreak of Carbapenem Resistant Klebsiella pneumoniae with Whole Genome Sequencing” (Science Translational Medicine, August 2012), Dr. Evan Snitkin and co-authors analyzed a 2011 outbreak of antibiotic resistant bacteria in the National Institutes of Health Clinical Center that affected 18 patients, 11 of whom died. Nicole Mahoney, Senior Officer of Pew's Antibiotics and Innovation Project, discusses the report.
Mahoney: This report gives more urgent proof that we need a comprehensive strategy for fighting antibiotic resistant bacteria, also known as superbugs. The NIH reported on an antibiotic-resistant infection outbreak that they had in their clinical center in 2011. They outlined the spread of the bacteria, which they tracked through modern genetic techniques, and they talked about how the infection spread from patient to patient despite their best infection-control efforts.
Q: What can superbugs do to someone who gets infected?
Mahoney: These patients were infected with an antibiotic-resistant bacterium called Klebsiella, a type of bacteria that's deadly in a lot of cases because the drugs we have today are often not effective for treating it.
Q: What does this tell us about what strategies we need to fight antibiotic-resistant infections?
Mahoney: This paper shows us that despite our best efforts at infection control, bacterial outbreaks happen. It also reminds us just how big a threat antibiotic resistance is. What we need is a comprehensive, three-part strategy for tackling antibiotic resistance. First of all, we need good infection-control measures. That means we need to contain infection outbreaks and we need to prevent the spread of infections in our health care facilities. The second thing we need is to use antibiotics wisely. Every time you use an antibiotic, you increase the chances of causing antibiotic resistance, so we want to use them minimally and sparingly to make sure that they're effective in the future. And the third thing we need is a stream of new antibiotics to combat emerging threats and infections, and superbugs.
Q: Can you quantify the lack of antibiotics?
Mahoney: We're always going to need new antibiotics, and unfortunately fewer have been coming to market in the last few decades. In the 1980s, 29 new systemic antibiotics came to the market. In the 1990s, that number dropped to 23, and from 2000 to 2010, only nine antibiotics were approved for use in this country.
Q: What are the challenges we're facing?
Mahoney: There are three major sets of challenges that face antibiotic drug developers: scientific, economic and regulatory. On the scientific front, it's very difficult and expensive to discover new antibiotics. There are plenty of fundamental scientific questions about bacterial infections that we're still struggling to answer. The second challenge is economic. Drug developers have a lot of economic disincentives for getting into this field. That's because antibiotics command lower prices than some other drugs, and they're also not taken as long as drugs for chronic diseases. The third challenge is regulatory. Antibiotics are different than some other drugs because of antibiotic resistance and other factors, and we really need to make the pathways for how companies need to test these drugs for safety and effectiveness very, very clear. Companies do not invest in the face of regulatory uncertainty. The FDA and companies need to work together, to figure out clear pathways to get new antibiotics to market.
Q: Are there any drugs that worked for these patients? What's the take-away here?
Mahoney: The patients that were discussed in this study were treated with a drug of last resort called colistin. Some developed infections that became resistant to that drug, leaving no other options. At least one patient who contracted a colistin-resistant infection died of the infection, though another survived. Doctors typically reserve colistin for when they don't have any other treatment options -- when bacteria are resistant to all other drugs -- and the reason is because it causes kidney damage. What this tells us is we desperately need new antibiotics because when drugs of last resort fail, there's really nothing left.
Learn more about the superbug outbreak and the need for new antibiotics with the related resources below.