|MOLNAR, ADEL - Framingham State College|
|CHOI, HWANG-YONG - Framingham State College|
|RACICOT, KENNETH - United States Army Center For Health Promotion And Preventative Medicine|
|APOSTOLIDIS, EMMANOUIL - Framingham State College|
Submitted to: Antibiotics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2019
Publication Date: 11/29/2019
Citation: Rasooly, R., Molnar, A., Choi, H., Do, P.M., Racicot, K., Apostolidis, E. 2019. In-vitro inhibition of staphylococcal pathogenesis by witch-hazel and green tea extracts. Antibiotics. 8(4):244. https://doi.org/10.3390/antibiotics8040244.
Interpretive Summary: The World Health Organization ranks bacterial resistance to antibiotics as one of the top three health care concerns worldwide, with staphylococcal infections being the largest contributors to this growing problem. According to the CDC, of the estimated annual 2 million hospital-acquired infections in the U.S., approximately one half are due to staphylococcal bacteria that form biofilms and produce toxins, making them even more resistant to antibiotics and more deadly. In this study we show that extracts of witch-hazel and green tea inhibit biofilm formation and toxin production by S. aureus and S. epidermis. Both extracts have antimicrobial effects and that inhibitory effect is synergistic. These plant extracts can thus be used as alternatives to antibiotics, to treat or prevent both chronic (biofilm-associated) and acute (toxin-associated) infections.
Technical Abstract: whISOBAX (WH), an extract of witch-hazel plant that is native to the Northeast coast of the United States, contains significant amounts of a phenolic compound Hamamelitannin (HAMA). Green tea (GT) is a widely consumed plant that contains various catechins. Both plants have been associated with antimicrobial effects. In this study we test the effect of these two plant extracts on the pathogenesis of staphylococci, and evaluate their effect on bacterial growth, biofilm formation and toxin production. Our observations show that both extracts have antimicrobial effect against both strains of S. aureus and S. epidermidis tested, and that this inhibitory effect is synergistic. Also, we confirmed that this inhibitory effect does not depend on HAMA, rather on other phenolic compounds present in WH and GT. In terms of biofilm inhibition, only WH exhibited an effect and the observed anti-biofilm effect was HAMA depended. Finally, among the tested extracts, only WH exhibited effect against Staphyloccocal Enterotoxin A (SEA) production and this effect correlated to the HAMA present in WH. Our results suggest that GT and WH in combination can enhance the antimicrobial effects against the tested Staphylococcal strains. However, only WH can control biofilm development and SEA production, due to the presence of HAMA. This study provides the initial rationale for the development of natural antimicrobials for the food industry, to control biofilms and toxins production from Staphylococcal strains.