Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics



Thesis Sponsor/Dissertation Chair/Project Chair

Lee H. Lee

Committee Member

John Gaynor

Committee Member

Sandra Adams


Epigallocatechin gallate, Artificial joints--Infections, Staphylococcus aureus, Pseudomonas aeruginosa


Approximately 1-2% of patients have complications due to bacterial infection. Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa are the three bacteria responsible for approximately 75% of biofilm-related infections. These three microorganisms can adhere to stainless steel and orthopedic screws. Biofilms are produced by an accumulation of bacteria which can attach to a surface, accumulate and form an extracellular polymeric substance.

Green tea extracts from plant Camellia sinensis have long been studied for their antimicrobial effect on gram-positive and gram-negative bacteria. Polyphenols found in green tea, specifically epigallocatechin-gallate (EGCG), are the most important component in targeting biofilm. However, this compound can be readily oxidized and is therefore unstable. Previous studies have shown that the modified lipophilic compound, epigallocatechin-gallate-stearate (EGCG-S), can inhibit biofilm formation and decrease cell viability.

The purpose of this study was to evaluate if EGCG-S could play a role in targeting prosthetic joint infection caused by Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. Major goals of this study were to determine if EGCG-S could enhance the current treatment method and inhibit biofilm in addition to two virulent factors. The minimum time frame was also determined for treatment to be most effective. EGCG-S was shown to have some inhibitory effects on colony forming units, the most effective time for treatment was observed starting at five minutes. The tea polyphenol was also able to inhibit biofilm and protease and elastase when the three bacteria were in combination. EGCG-S shows potential for combating acute and chronic joint arthroplasty infections.

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