Utah Health and Wellness
4:55 pm
Wed December 11, 2013

Antibiotic Resistant Bacteria Becoming A Looming Public Health Threat

Human neutrophil ingesting MRSA.
Credit 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 kept in check for nearly a century.

“It’s rare that we know of someone in the United States who dies of an infectious disease. This used to not be the case, a hundred years ago infectious diseases used to be the primary cause of death,” said Matt Mulvey, a University of Utah researcher.

Mulvey studies bacteria and is trying to understand how they cause disease and become resistant to antibiotics. He said 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. 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,” Mulvey said.

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, 3 years ago and he ended up dying within about seven days of receiving this, despite antibiotic treatments,” he said.
 
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. Mulvey said 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. And I think we need to work hard to prevent that from happening,” he said.

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 said 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,” he said. “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 patients take an antibiotic, it wipes out bacteria in the 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 its 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. So this is why physicians should be very careful about prescribing antibiotics unnecessarily. An individual also needs to be very careful about harping on their physicians hoping to get antibiotics out of them because they feel sick,” he said. “Antibiotics are only going to work against the right bacteria and they are useless against viruses.”

Mulvey said 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. 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,” Mulvey said.

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 have a comprehensive system to track resistant infections that occur in the country.

Rep. Jim Matheson (D-Utah) said he 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 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. And we really need a coordinated, cooperative effort across the country to define the problem,” Matheson said. “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.”

However, if action is to be taken, Mulvey said it should be taken quickly. There are recent reports of bacterial strains that are resistant to all antibiotics in the public health arsenal.

“It was taken from, of all places, an estuary in the ocean off the coast of North Carolina in very polluted waters. And it’s resistant to every known antibiotic on the planet, and not only that, it’s resistant at record levels of these antibiotics,” Mulvey said.

While it’s not known if this specific bacteria causes 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.