GUILDFORD, England — Antibiotic-resistant bacteria have become a greater focus among doctors and health-focused scientists in recent years. However, researchers at the University of Surrey in England may have found a secret weapon in the fight against these persistent microbes: green tea. According to their new study, epigallocatechin (EGCG), a natural antioxidant commonly found in green tea, can help eliminate antibiotic resistant bacteria.
Researchers say that antibiotic-resistant bacteria are a major health problem due to how frequently antibiotics are being used to treat bacterial infections. In response, some bacteria have actually adapted and become resistant to antibiotics.
Researchers discovered that the EGCG found in green tea can restore and strengthen the activity of aztreonam, an antibiotic commonly-used to treat serious respiratory tract and bloodstream infections caused by the bacterium Pseudomonas aeruginosa. In recent years, P. aeruginosa has become resistant to many major classes of antibiotics.
Right now, a combination of different antibiotics is being used to treat Pseudomonas aeruginosa cases, but the bacterium is becoming increasingly hard to stop, and is even showing resistance to last-line antibiotics.
Researchers led by Dr. Jonathan Betts, a Senior Research Fellow at the School of Veterinary Medicine at the University of Surrey, assessed the compatibility of EGCG and aztreonam by conducting in vitro tests that analyzed how the substances interacted with P. aeruginosa, both individually and in combination. They found that a combination of the two was much more effective at lowering bacteria numbers than either agent alone.
The research was conducted on Greater Wax Moth larvae and human skin cells. Larvae survival rates were much higher among specimens treated with a combination of the EGCG and aztreonam. Furthermore, virtually no toxicity was observed in the skin cells or in the larvae after receiving combined treatments.
Dr. Betts’ team hypothesize that EGCG facilitates elevated uptake of aztreonam by increasing permeability within the bacteria. They also theorize that green tea antioxidant may interfere with a biochemical pathway associated with antibiotic susceptibility.
“Antimicrobial resistance (AMR) is a serious threat to global public health. Without effective antibiotics, the success of medical treatments will be compromised. We urgently need to develop novel antibiotics in the fight against AMR,” says Dr. Betts in a university release. “Natural products such as EGCG, used in combination with currently licensed antibiotics, may be a way of improving their effectiveness and clinically useful lifespan.”
“The World Health Organization has listed antibiotic-resistant Pseudomonas aeruginosa as a critical threat to human health. We have shown that we can successfully eliminate such threats with the use of natural products, in combination with antibiotics already in use. Further development of these alternatives to antibiotics may allow them to be used in clinical settings in the future,” comments Professor Roberto La Ragione, head of the Department of Pathology and Infectious Diseases in the School of Veterinary Medicine at the University of Surrey.
The study is published in the Journal of Medical Microbiology.