From multicellular organisms, like us humans, to single-cell bacteria, living things are subject to attack by viruses. Plants, animals and even bacteria have evolved strategies to combat pathogens, including viruses that can threaten health and life. Talia Backman, a University of Utah doctoral candidate wrapping up her final year in the School of Biological Sciences, found her project and niche in studying bacteria and the viruses that infect them.

She studies how bacteria create and use weapons, called “tailocins,” by repurposing genes from viruses.

“I’m especially interested in how bacteria have taken this a step further,” Backman said, “using remnants of past viral infections as a novel defense mechanism.”

“Phage” is the word that refers to the viruses that infect bacterial cells. While phages do not attack human cells, a lot can be learned from the strategies used by bacteria to survive a viral infection. Working with Talia Karasov, the principal investigator and assistant professor of biology (yes, they share the same first name), Backman recently helped make an unexpected discovery.

“We looked in the genome [DNA of bacteria] …and learned that the bacteria had taken a phage and repurposed it [using gene recipes from the phage] for warfare with other bacteria, now using it to kill competing bacteria,” Karasov said.

Repurposing viruses

“The bacterial strains (Pseudomonas) that I am studying are essentially repurposing the viruses that infect them,” Backman said, “retaining features from the infectious particles that ultimately help them to kill or co-exist with other strains of bacteria. These repurposed phage parts are called ‘tailocins.’ Understanding the role tailocins may be playing in shaping the prevalence, survival, and evolutionary success of certain bacterial strains is not well understood and is a major focus of the research in the Karasov lab.

“What we know, and are learning about microbes,” Backman continued, “is considered ‘foundational or basic science,’ but it’s anything but ‘basic.’ Understanding how life works can lead to new ideas and innovations. Today, human health, and the medicines we rely on, are challenged by the failure of antibiotics, medicines critical in combating bacterial infection.”

New class of antibiotics

Research on bacteria, and their unique viral pathogens, might just offer a novel solution to the antibiotic crisis. Beyond revealing how microbial communities combat infection, compete and evolve is the adjacent opportunity and potential to discover a new class of antibiotics.

“Perhaps tailocin therapy and training our cells to identify and destroy bacterial invaders by using bits and pieces from the pathogens that infect us,” Backman said, “will be the next generation in antibiotic medications.”

Antibiotics have been a medical miracle since the mid-20th century. However, Hanna Balky, the World Health Organization (WHO) assistant director-general on antimicrobial resistance, cautions that “there is a major gap in the discovery of antibacterial treatments, and more so in the discovery of innovative treatments. This presents a serious challenge to overcome the escalating pandemic of antimicrobial resistance and leaves every one of us increasingly vulnerable to bacterial infections including the simplest infections.”

Basic science is paving the way for novel solutions to global challenges, like antibiotic resistance.

“My research, and ongoing efforts in labs like Dr. Karasov’s in the School of Biological Sciences,” Backman said, “is at the forefront of providing insight into the mechanisms that organisms use to live, reproduce, and overcome infection.”

The future for Talia Backman, who plans on completing her doctorate in May, looks bright.

“Once I finish with my PhD research next summer, I look forward to pursuing a career that will allow me to continue to do part-time research and part-time teaching,” she said. “I hope to inspire students to appreciate the pursuit of knowledge and not be afraid of digging deep into the molecular mechanisms that can inform solutions to today’s grand challenges.”

This research, titled “A phage tail-like bacteriocin suppresses competitors in metapopulations of pathogenic bacteria,” was published in the journal Science, on June 14, 2024. The research, which was funded by the National Institutes of Health, was also featured in @theU and on earth.com.