Des Field


My research within APC Spoke 1 (Microbes to Molecules) primarily focuses on the distinct class of antimicrobial peptides or bacteriocins (antimicrobial agents produced by bacteria that kill other bacteria) known as lantibiotics. Lantibiotics are peptides that are distinguished by the presence of unusual amino acids and have become the focus of much biomedical and pharmaceutical research due to their high potency in vitro, numerous modes of action and capacity to destroy target cells rapidly. The most extensively characterised and utilised lantibiotic is nisin. Nisin is used commercially in food products as it is active against many types of food spoilage pathogens. Nisin also exhibits antimicrobial activity against many Gram-positive human and animal pathogens

Currently, nisin is of interest for clinical applications due to its potent activity against multi-drug resistant bacteria but also more recently for its potential for the in vivo modulation of animal microbiota when nisin is orally administered. Consequently, our work has focused on engineering nisin for resistance to proteolytic destruction by the digestive enzymes trypsin and chymotrypsin as well as specific enzymes harboured by many pathogenic strains including the nisin resistance protein (NSR) and NsrFP. Future work will focus on the application of different nisin derivatives that exhibit enhanced antimicrobial activity and/or resistance to proteolytic enzymes in a bid to beneficially modulate the gut microbiota in vitro and in vivo.

Research Interests

Theme: Microbes to Molecules

SDGs: Sustainable Development Goal 3. Health and Wellbeing since several studies have shown that although broad spectrum bacteriocins like nisin can have a negative effect on the resident intestinal populations, they have exhibited promise with respect to their ability to improve metabolic health. Indeed, nisin has been seen to influence the microbiota, often beneficially, in the majority of in vivo studies including those on mice, chickens and rabbits and in in vitro bovine and human microbiota studies.

Research key words: Bacteriocins, antimicrobial peptides, Gut microbiota, probiotic, antimicrobial resistance, lantibiotic, nisin,





APC Microbiome Ireland, Biosciences Building, University College Cork, Ireland,