New research highlights discovery of antibiotic targeting antibiotic-resistant bacteria

New research from a School of Dentistry expert launches a strong defense in the fight against antibiotic resistance.

Sven-Ulrik Gorr, PhD, professor of basic sciences, is the author of "Resisting the resistance: The antimicrobial peptide DGL13K selects for small colony variants of Staphylococcus aureus that show increased resistance to its stereoisomer LGL13K, but not to DGL13K." The article was accepted in the Journal of Bacteriology and published in June 2025.

The article is the latest in Gorr’s work to understand and combat antibiotic-resistant bacteria. 

“Antibiotics have been around for almost 100 years, but bacteria are very good at developing resistance, and we continually have to try and outsmart the bacteria with new antibiotics,” Gorr explained. The battle—which some call the “climate change of medicine: a looming disaster that has already started but for which we do not yet have good solutions”—has been strenuous and difficult.

Gorr and his team developed an antimicrobial peptide, DGL13K—also known as Minneganan—an antibiotic that kills bacteria that are resistant to traditional drugs. “The question was if the bacteria could also become resistant to Minneganan,” as they have to previous antibiotics. 

The study determined that, while bacteria did become resistant to the left-handed version Minneganan, bacteria were unable to resist its mirror image, the right-handed version (DGL13K). “Surprisingly, bacteria treated with either version try to defend themselves with mutations, but these are only effective against the left-handed version,” he said. The staphylococci used in this study are the fourth bacterial species, including oral streptococci, that are unable to resist DGL13K.

This finding is significant in the fight against antibiotic resistance in bacteria because it opens up possibilities for the creation of antibiotics that bacteria can’t fight. “Bacteria have a repertoire of defenses to antibiotic challenges, but this study suggests it is possible to design antibiotics that overcome them,” Gorr explained. “We call this ‘resisting the resistance.’” 

Knowing that an antibiotic to which a bacteria cannot develop resistance exists opens significant possibilities for clinical care. “Antibiotics are unique drugs because they lose effectiveness in the population as they are used more,” Gorr said. “This requires careful stewardship of these drugs and makes for a challenging area of development. An antibiotic that does not cause resistance could have much longer clinical use time than current antibiotics, which typically start losing their effectiveness in the first decade after introduction.” 

Moving forward, Gorr and his team will explore the best uses for Minneganan, as well as how mutations affect the bacterial cell. He will continue to prioritize collaboration, with an understanding to its value in research. 

“This work takes advantage of the amazing support ecosystem at the University of Minnesota,” he reflected. “This includes time to pursue independent research, pilot funds from the dental school to pursue new ideas and a grant from the genomics center to study the bacterial genome. Our collaboration with clinicians is also critical to ensure our work is focused on real-life problems.” 

Dr. Gorr is Chief Scientific Officer of and holds equity in Gavia BIO, which is developing the antimicrobial peptide Minneganan (DGL 13K). These interests have been reviewed and managed by the University of Minnesota in accordance with its Conflict of Interest policies.