Antimicrobial peptide naturally found in cows breaks Klebsiella biofilms and kills drug-resistant bacteria

Antimicrobial peptide naturally found in cows breaks Klebsiella biofilms and kills drug-resistant bacteria Stephanie Baum Scientific Editor Robert Egan Associate Editor UCF College of Medicine Assistant Professor Renee Fleeman continues to refine a powerful therapy for drug-resistant bacteria that pierces the gooey coating that anchors and protects such germs from the drugs we take to kill them. Her research has found that an antimicrobial peptide naturally found in cows weakens the biofilm defenses of Klebsiella pneumoniae bacteria and destroys it. Now in their fourth year of research, Fleeman and her lab have discovered exactly how the peptide works in findings recently published in PLOS Pathogens. "Our research is very advantageous for health care, because about 80% of bacterial infections being treated in the clinic are bacteria living in a biofilm state, which makes them resistant to virtually every antibiotic available," she said. The results represent a critical step to potentially applying this peptide as a therapy and eventually treating patients, as the findings show they can weaken and kill biofilm-embedded bacteria in animal models. Parsing out the peptide K. pneumoniae is found in the intestines and is usually harmless. However, the bacterium develops resistance over a person's lifetime as they are exposed to antibiotics. The bacteria can also spread from the intestine to other parts of the body in immunocompromised patients and those who have internal ruptures or exposure to contaminated medical devices. That exposure can lead to pneumonia, wound, or urinary tract infections. "What happens is the bacteria infects the wound, proliferates, and then invades through the bloodstream where it travels to the liver, kidneys, and spleen," Fleeman said. "We found that our peptide was able to decrease the bacteria at the source while limiting the bacteria's ability to move through the blood." The team's most recent study found that the peptide triggers a dual stress response that tricks the bacteria to break out of their protective biofilm. They discovered the genetics of a specific protein in the bacterium, that when turned on in the germ, causes it to break from its own protective biofilm. The peptide, in effect, damages the protection and then stresses the bacterium into shedding its protection, making the germ more sensitive to antibiotics and the body's 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 as a response to our peptide," Fleeman says. The team says their sustained research aims to demonstrate that their peptide can work synergistically with existing antibiotics. They envision long-term applications could involve a topical cream that weakens the bacteria's defenses and allows standard antibiotics to work more effectively. "We're moving our research forward and we're very hopeful," Fleeman said. Publication details Robert L. Beckman I.V et al, Molecular response to the non-lytic peptide bac7 (1–35) triggers disruption of Klebsiella pneumoniae biofilm, PLOS Pathogens (2025). DOI: 10.1371/journal.ppat.1013437 Journal information: PLoS Pathogens Key concepts Host-Pathogen InteractionsProvided by UCF College of Medicine