Laboratory for New Antibiotic Technologies

The discovery of antibiotics is one of the most important ones in the history of humankind. For eighty years the life expectancy and the standards of living of humans have greatly improved thanks to antibiotics.


But the age of antibiotics may be over because of the emergence of antibiotic-resistant  strains and the paucity in new drug development. New and alternative strategies must be explored as antibiotic therapies become obsolete because of bacterial resistance.


We use chemical engineering principles to model, design, construct and test new antimicrobial technologies. We are focusing on naturally occurring antibiotics, such as antimicrobial peptides (AMPs), and on smart delivery vehicles, such as recombinant probiotic bacteria.

Lactococcus Lactis
In this picture Lactococcus lactis (white) drawn in the shape of the Asclepius’ rod (a common symbol of health and medicine) on a field of pathogenic Enterococcus faecalis (blue). L. lactis has been engineered to produce antimicrobial peptides that result in a zone of pathogen inhibition surrounding L. lactis. Bacteria were plated on brain heart infusion agar containing X-gal to result in coloration of β-galactosidase-producing E. faecalis. Photograph taken by Kathryn Geldart with editing by Jeffrey Ting, University of Minnesota.


We design antimicrobial peptides to target multi-drug resistant pathogens. We cannot administer these peptides orally because as proteins they are degraded in the stomach of hosts. Instead we recruit probiotic bacteria and engineer them as the production factories and delivery vehicles of AMPs. Probiotics are non-virulent, bile resistant bacteria that can survive passage through the stomach and reach the GI tract of hosts. The GI tract is where the vast majority of pathogens reside. We use synthetic biology techniques to modify probiotics to produce and secrete AMPs at the site of infection.


We are currently collaborating with clinicians to fight enterococcal infections and urinary tract infections. We are also collaborating with veterinarians to fight salmonella and clostridia infections in livestock.




July 2017 News


The free energy of binding between antimicrobials and bacterial proteins is an important physicochemical property that dictates the efficacy of a drug molecule agains pathogens. We recently completed a study of the free energy of Microcin J25, a potent antimicrobial peptide, binding on FhuA, a membrane protein found on the cell membrane of Salmonella. We investigated how mutations on Microcin J25 impact the antimicrobial activity against pathogenic Salmonella, and identified mutations that make the peptide significantly more active. We are now experimenting in the lab with the new Microcin variants. Find more information here.

March 2017 News

We recently completed an investigation of the molecular mechanism used by pathogenic Enterococcus faecium to develop resistance against enterocins.  Understanding the mechanisms bacteria use to resist antibiotics helps us design new antimicrobials that can kill multi-drug resistant pathogens. The manuscript was published in Antimicrobial Agents and Chemotherapy (

December 2016 News

We recently completed our first large-scale animal study. The results are published in Nature's Scientific Reports ( We successfully designed, built and tested antimicrobial probiotics in turkey poults. We have shown that our technology eliminates 97% of Salmonella enterica from the ceca in the GI tract of treated birds. Salmonella is the number one foodborne pathogen. Poultry is the number one source of salmonella. The ceca is the main repository of salmonella in poultry. This proof-of-concept demonstration paves the way for more animal studies and preclinical trials.


November 2016 News


We recently published a manuscript in Pharmaceuticals presenting pMPES, a synthetic biological construct for modular design of antimicrobial probiotics. This is the first time a Gram-negative probiotic produces and secretes multiple antimicrobial probiotics with orthogonal mechanisms of action. This antimicrobial probiotic targets foodborne pathogens Salmonella enterica and E. coli. Find more information at