Antibiotic Resistance, A Looming Public Health Threat

26 November 2013
Published in Health
Written by  Kim Schuske
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Antibiotic Resistance, A Looming Public Health Threat Human neutrophil ingesting MRSA (NIH)

Antibiotics are our main line of defense against bacteria that can make us very sick. But that defense is breaking down as the microorganisms are increasingly becoming resistant to our most effective drugs. How we deal with this threat may determine if we will become at risk of dying from infectious diseases that have been held in check for nearly a century.

Matt Mulvey is a researcher at the University of Utah who studies bacteria and is trying to understand how they cause disease and become resistant to antibiotics.

"It's rare that we know of someone in the United States who dies of an infectious disease," says Mulvey. "This used to not be the case. One hundred years ago infectious diseases used to be the primary cause of death."

The Centers for Disease Control recently reported that every year around 2 million people acquire antibiotic-resistant infections and 23,000 die from these infections.

"It does scare me actually, it does scare me more and more," says Mulvey. "One of my daughters and my wife recently had pneumonia and the first thing that goes through my mind is, 'Geez I hope this is susceptible to antibiotics.'"

Luckily they were diagnosed with bacterial pneumonia that was easily treated with the appropriate antibiotics. But, his fears are justified.

"My older brother had pneumonia about 2 or 3 years ago and he ended up dying within about seven days of receiving this, despite antibiotic treatments."

Mulvey says bacterial strains, resistant to certain antibiotics, have been on the rise over the last few decades and new drugs are not being developed to combat these now-resistant bugs. The concern is that without effective antibiotics, cancer treatments, major surgeries, and even a small cut could become dangerous.

"We don't want to see infectious diseases rise up again in this country or anywhere else," says Mulvey. "And I think we need to work hard to prevent that from happening."

Penicillin was the first antibiotic developed and was in widespread use by 1943, but the first resistant strains were identified three years earlier in 1940. Mulvey says that's the problem with bacteria, they divide rapidly giving them an evolutionary advantage against drugs.

"Bacteria acquire genes that allow them to circumvent or prevent antibiotics from coming into the bacteria cells," explains Mulvey. "Or if these antibiotics do come in, the bacteria can pump them out or otherwise inactivate the antibiotics. So this is natural selection at work, this is evolution."

When we take an antibiotic, it wipes out bacteria in our body that are sensitive to it, even the good bacteria. This means that the random resistant bacteria floating in our system will survive and now be able to thrive because it's growth is not kept in check by all of the other bacteria it was competing with for resources. Frequent antibiotic use can increase the risk of eventually developing a resistant infection.

"You can in an individual select for antibiotic-resistant microbes," says Mulvey. "So this is why physicians should be very careful about prescribing antibiotics unnecessarily." He adds, "An individual also needs to be very careful about harping on their physicians hoping to get antibiotics out of them because they feel sick. Antibiotics are only going to work against the right bacteria and they are useless against viruses."

Mulvey says his lab and others are doing basic research to figure out new ways to attack bacteria. They are identifying those genes and gene products that bacteria need to cause disease. Some of these factors may become targets that they could theoretically develop drugs against.

"The ideal drug would be one that kills only the pathogen, leaving our commensal bacteria, the good guys that live inside our intestinal tract, and on our skin and in our mouth. These are important to our health," says Mulvey. "If we could target the pathogens while leaving the good guys alone, that would be wonderful. Most antibiotics we have now days don't do that. They are scorched earth policy, they destroy everything they come in contact with."

Only one antibiotic has been developed and approved for use since 2010, and few new antibiotics are in the pipeline. Bacterial resistance is becoming a public health threat that even congress is starting to recognize. Last year, there was a provision in the Food and Drug Administration Safety and Innovation Act that provided some incentives for developing new antibacterial drugs. But, these are just small steps. Currently the U.S. doesn't even have a comprehensive system to track resistant infections that occur in the country.

Utah Representative Jim Matheson thinks we need to get a better handle on the scope of the problem. He introduced a bill in June called the STAAR Act, for Strategies to Address Antimicrobial Resistance. The goals of the act are to support the combined efforts of scientists, health practitioners, and governing bodies in tracking resistant bacteria, limiting antibiotic use, and coming up with new approaches to address the impending problem.

"Lets help define the problem, because right now there's all sorts of data points out there across the country and nobody is coordinating them," says Matheson. "And we really need a coordinated, cooperative effort across the country to define the problem. And I think if we better define the problem, that's going to lay the groundwork for how to best set up incentives to get that next generation of antibiotics developed."

But, we better move fast, because there are recent reports of bacterial strains that are resistant to all antibiotics we have in our arsenal.

"It was taken from, of all places, an estuary in the ocean off the coast of North Carolina in very polluted waters," says Mulvey, describing a recently identified bacterial strain. "And it's resistant to every known antibiotic on the planet, and not only that, it's resistant at record levels of these antibiotics."

While it's not known if this specific bacteria cause disease, individuals infected by gram negative bacteria that are resistant to all available antibiotics have been showing up around the world, including in the US.

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