UCF Scientist Discovers Cow Peptide Breaks Bacterial Defense

A University of Central Florida researcher has identified how a peptide derived from cows can penetrate the protective coating that shields drug-resistant bacteria from antibiotics.

Renee Fleeman, an assistant professor at UCF's College of Medicine, published the findings in PLOS Pathogens. The peptide triggers a dual stress response that forces Klebsiella pneumoniae bacteria to abandon their biofilm defenses, Fleeman said.

About 80 percent of bacterial infections treated in clinics involve biofilm-state bacteria, which resist nearly every available antibiotic. The peptide damages the bacteria's membrane while simultaneously stressing the organism into shedding its protective layer, leaving it vulnerable to antibiotics and the immune system.

"By hitting the membrane as well as protein synthesis at the same time, it's a double punch that triggers a genetic change in the cell to make it think it needs to break out of the biofilm," Fleeman said.

Tests in animal models showed the peptide killed biofilm-embedded bacteria and prevented them from spreading through the bloodstream to organs. K. pneumoniae normally lives harmlessly in human intestines but can cause pneumonia, urinary tract infections, and wound infections when it spreads in immunocompromised patients or those with internal ruptures or contaminated medical devices.

Fleeman's team envisions developing a topical cream that weakens bacterial defenses and allows standard antibiotics to work more effectively. Robert Beckman, who graduated from UCF in 2023 with a bachelor's degree in health sciences, served as first author on the study. He managed Fleeman's lab before beginning doctoral work at the University of Michigan.

The National Institute of Allergy and Infectious Diseases funded the research with a five-year, $813,130 grant. Fleeman and her team are in their fourth year of work and continue testing whether the peptide can work with existing antibiotics.