Student(s): Elizabeth Sterner
Project: Utilizing Michaelis-Menten Kinetics to Compare Efficiency of Beta-Lactamase Inhibitors Against Pseudomonas aeruginosa
Advisor(s): Angela Brown
Abstract
According to a 2025 report by the World Health Organization, antibiotic resistance remains an increasing threat to public health worldwide. Enzymatic degradation is a common antibiotic resistance mechanism. Inhibition of these enzymes has the potential to limit this mechanism of resistance. Relebactam is a commonly used but more expensive inhibitor compared to cheaper 3-carboxyphenylboronic acid. It was unknown if 3-carboxyphenylboronic acid would work in a comparable capacity to relebactam. The goal of this research was to compare their efficiencies in several strains of Pseudomonas aeruginosa, an antibiotic-resistant Gram-negative bacteria. Nitrocefin, a cephalosporin antibiotic that changes color with degradation, was used to monitor the rate of reaction. Absorption at 486 nm was measured to monitor the rate of degradation for a series of nitrocefin concentrations. Michaelis-Menten kinetics were used to compare the degradation rates with increasing inhibitor concentration and conclude on the type of inhibition occurring. Additional analysis was completed between inhibitor types for each bacterial isolate to compare efficiency. The results demonstrated that a variety of inhibition mechanisms occur for the isolate and inhibitor combinations, with competitive, non-competitive, and mixed inhibition present in the results. The data also indicated that relebactam is a more efficient inhibitor compared to 3-carboxyphenylboronic acid. Overall, these findings support the use of enzymatic inhibitors to combat enzymatic degradation of antibiotics. Insight was also gained on the mechanisms of inhibition, providing valuable information for further research applications and advancements to combat antibiotic resistance.
About Elizabeth Sterner
Major: Chemical and Biomolecular Engineering
Elizabeth Sterner is a third year undergraduate student studying chemical engineering at Lehigh University. She is currently researching mechanisms of antibiotic resistance in Gram-negative bacteria, including Pseudomonas aeruginosa, in the Brown Lab. The goal of this work is to gain insight into the mechanisms of enzymatic inhibitors that will be used to combat antibiotic resistance. She anticipates expanding her current research to outer membrane vesicle applications in the future. After graduation, Elizabeth hopes to apply her chemical engineering education in a food science capacity within the food product development field. She is from Bethlehem, Pennsylvania and graduated from Salisbury High School in 2023. Elizabeth is also a Girl Scout Gold Award alum. Outside of research, she is the Outreach Lead of Lehigh Baja SAE and enjoys baking, reading, being outdoors, and spending time with her family and friends.