Mariana Perez Ibarreche
Research Title: Inhibition of Pathogens Nisin resistant by nisin derivatives obtained by Bioengineering.
Project Summary: Antimicrobial resistance poses one of the biggest threats to global health today. According to the World Health Organization antibiotic resistance in the European Union alone, is estimated to cause 25,000 deaths and cost more than USD 1.5 billion every year in healthcare expenses and productivity losses. Without effective antibiotics for the prevention and treatment of infections, many of the achievements of modern medicine such as organ transplantations, chemotherapy and surgeries such as caesarean sections become much more dangerous. An alternative to this method would be to use antimicrobial compounds with a different mechanism of action than antibiotics to avoid the resistance developed by microorganisms. An alternative of that is the use of bacteriocins. Nisin is the most prominent member of bacteriocins and demonstrates significant potential as a clinical and food antimicrobial. However, some bacterial strains have been reported to be congenitally resistant to it. The last reported cases of nisin resistance were the identification of two-component systems (TCS) forming by two membrane associated proteases: nisin-resistant protein (NSR) and NsrFP (BceAB-type ABC transporter). NSR cleaves the last six amino acids of nisin resulting in nisin1-28, which has a 32-fold lower activity. This product of NSR (nisin1-28), is still recognized by NsrFP. The main objective of this work is to evaluate the inhibitory capacity of nisin derivatives on pathogens harboring NSR-like protein. Also, considering biofilm as the predominant form of growth of pathogens, the activity of nisin derived alone and in combination with other antimicrobial agents will be evaluated.