The World Health Organization (WHO) recently released a list of bacteria “for which new antibiotics are urgently needed.” The WHO’s first-ever prioritized list of antibiotic-resistant pathogens highlights critical areas of focus for scientists around the globe. For many researchers at Texas Medical Center institutions, the list reaffirms the strategies they are already implementing to address this significant threat to global health.
Antibiotic-resistant bacteria infect at least 2 million people each year, and at least 23,000 of those people die from their infections, according to the Centers for Disease Control and Prevention (CDC). The WHO’s list is intended to encourage both the private and public sectors to increase funding for research into new drugs and methods for stopping this growing threat.
“This sets the tone and gives justification as an impartial assessment of the problem on a global basis,” said Vincent H. Tam, Pharm.D., a professor in the Department of Pharmacy Practice and Translational Research at the University of Houston College of Pharmacy. “It gives funding agencies a reason to focus on initiatives and channel resources to targeting this problem.”
The list divides 12 pathogens into three priority tiers: critical, high and medium. All three of the pathogens listed as critical are resistant to the carbapenem type of antibiotic. This is significant, because this class of antibiotics is often the drug of last resort for bacterial infections.
“Carbapenems have been heavily relied upon in the past decade, if not longer, as our go-to drugs,” Tam said. “Now we are seeing that even our most reliable drug is losing efficacy. We either have to try options that are much more toxic, which we don’t like, or we have to use drugs that may not have a proven track record of effectiveness.”
Bacteria can become drug resistant in multiple ways, but it often boils down to mutation. For example, genes native to the bacterium can mutate and affect the drug’s ability to bind to the molecules it’s intended to target. Alternatively, the bacterium can acquire antibiotic-resistant genetic material from other bacteria.
“The immune system and a pathogen are in an arms race of evolution in which the immune system is constantly changing the antibodies that we produce, trying to make ones that are more and more effective at getting the pathogen, while the pathogen is constantly changing itself so that it can escape the next round of antibodies,” said Susan Rosenberg, Ph.D., Ben F. Love Chair in Cancer Research and a professor of molecular and human genetics, molecular virology and microbiology, and biochemistry and molecular biology at Baylor College of Medicine. “What antibiotics do is they kill cells or stop them from growing, reducing the number of a pathogenic bacteria the immune system has to cope with.”
When antibiotics are no longer effective, the balance tips toward the bacteria and the immune system can become overwhelmed.
Overuse of antibiotics is a contributing factor to the increased threat of antibiotic resistant bacteria, Tam and Rosenberg noted. This includes both overprescribing antibiotics to patients, as well as feeding them to livestock as a way to promote greater and faster growth.
“If your job is to grow chickens as quickly and large as possible, this is an efficient way to increase your profit margins,” Tam said. “But it is a short-sighted approach because, yes, we’ll get bigger chickens, but we’re going to have to pay a huge price down the road.”
The price? Enabling bacteria to mutate faster and more efficiently.
“Liberal use of antibiotics is almost certainly promoting resistance,” Rosenberg said. “Labs have shown that antibiotics can turn up the mutation rate in bacteria and cause resistance mutations, in addition to killing non-resistant competing bacteria, so it’s a bad idea to use antibiotics where they are not needed.”
At Baylor, Rosenberg’s work focuses on one of the strategies called for in the WHO report: to develop fundamentally new kinds of drugs to stop these pathogens.
“What we’re doing now is something very, very different,” Rosenberg said. “We’re trying to develop drugs that would slow down the bacteria’s ability to evolve.”
These new drugs have the potential to treat not only antibiotic-resistant bacteria, but also cancer, she said, by slowing down cancer cells’ ability to form new mutations and allowing the immune system to catch and eliminate them. The proliferation of cancer and bacteria, she added, are both “processes of evolution.”
Tam’s research at the University of Houston takes a different approach: repurposing drugs.
“We are looking at drugs that are already on the market and FDA-approved and trying to see if we can use these drugs to address some of the medical needs that we do not have solutions for,” Tam said. Strategies include trying to optimize older drugs by changing how they are used, as well as combining them with other agents to increase efficacy.
This touches on another of the WHO’s directives: ensuring “appropriate use of existing antibiotics in humans and animals,” since a singular approach will not solve what is becoming an increasingly widespread worry.
“It’s a good time to be thinking outside of the box on this problem,” Rosenberg said.
@bigdock Great news! Sending you our best wishes.
If you love citrus, you will really love these recipes with options from salad to stir-fry.
Women with darker skin can get #skincancer, too. Our Dr. Susan Chon shares what you should know: https://t.co/02BBg4YNmw @thirdAGE #endcancer
Overcoming #cancer shapes 3 MD Anderson employees’ perspectives: https://t.co/cUt1DJj9F1 #endcancer https://t.co/FmZgRjUw0b
University of Houston@UHouston
Legacy is planting seeds in a garden you never get to see. Tonight we’re celebrating the legacy of @UHValentiSchool. Thank you @seguntheprogram for being MC and @jdbalart for the Impact Award https://t.co/tBmWEylyiU
Entering a new era: learn more about TMC3, the new translational research campus. https://t.co/pCLaez3zts
Be a part of the nation's largest autism research study. Get in-person help with signing up for SPARK for Autism at the Houston Museum of Natural Science during their sensory friendly event April 28. http://bit.ly/SPARKevents
An Army Veteran confronts his own trauma with a camera https://t.co/qoMYFKKZjq via @nytimes
In this interview with @ktrhnews, Dr. James Langabeer of @UTHealth_SBMI and @UTEmergencyMed discusses the decline in prescriptions for addictive painkillers: https://t.co/CMlYcJngA4
At 10 months old, David was so weak and behind in development that he couldn't even sit up. But now the bubbly 4-year-old is growing fast and swinging baseball bats. Read about his miraculous journey w/@UTPhysicians CARE Clinic. https://t.co/3chQLYaeex #ManyFacesOfUTHealth https://t.co/LZptSVgsDY
RT @UTCVSurgery: Another great free medical screening service brought to you by @UTPhysicians! Check out Dr Stuart Harlin on this morning’s…
Veterans serving Veterans: Researchers who served. This @usairforce Veteran volunteered as a pararescueman in Vietnam, and then went on to serve others with a career in orthopedic research. https://t.co/2NQHhSTmQx via @VeteransHealth on #VAntagePoint
At 10 months old, David was so weak and behind in development that he couldn't even sit up. But now the bubbly 4-year-old is growing fast and already swinging baseball bats. Read about his miraculous journey with the UT Physicians CARE Clinic. #ManyFacesOfUTHealth
Today’s #VeteranOfTheDay is Navy Veteran Willard Knockum Jr. Willard served from 1964 to 1971 during the Vietnam War. Willard joined the Navy in 1964. He was trained in counterinsurgency and survival surveillance reconnaissance and weapons at the Marine Base Camp in Pendleton, California. He became a Boatswain Mate, a role that fulfills a variety of tasks such as lookout duty, training and directing maintenance duties, damage control, operating and maintaining equipment and more. Willard also participated in North Atlantic Treaty Organization and anti-submarine warfare exercises. Willard served on the destroyer USS Fox 779 before he deployed to Vietnam in 1969 during the Vietnam War where he served in Saigon and Dong Tam. He was assigned to Military Assistance Command, a group of assault river boats that patrolled hostile waters around the Army Base at Dong Tam. For his service, Willard was awarded the Vietnam Service Medal and the Republic of Vietnam Campaign Medal. Willard now lives in Folsom, Louisiana as a retired United Postal Service mail handler. Thank you for your service, Willard!
Today’s #VeteranOfTheDay is @USNavy Veteran Willard Knockum, Jr https://t.co/7lDPTdSI86