Since the early ages green tea has been known for its numerous health benefits. A recent study goes further and shows that it also could help to fight antibiotic resistant bacteria. DZIF scientists at the University Hospital Cologne and scientists at the University of Surrey have discovered that a natural antioxidant commonly found in green tea can help eliminate the antibiotic resistant bacteria Pseudomonas aeruginosa. The study has been published in the Journal of Medical Microbiology.
The study found that epigallocatechin (EGCG), a natural antioxidant commonly found in gree tea, can restore the activity of aztreonam, an antibiotic used to treat infections caused by the bacterial pathogen Pseudomonas aeruginosa. P. aeruginosa is associated with serious respiratory tract and bloodstream infections and in recent years has become resistant to many major classes of antibiotics. Currently a combination of antibiotics is used to fight P. aeruginosa. However, these infections are becoming increasingly difficult to treat, as resistance to last line antibiotics is being observed.
To assess the synergy of EGCG and aztreonam, researchers conducted in vitro tests to analyse how they interacted with the P. aeruginosa, individually and in combination. Professor Harald Seifert, DZIF scientist at the University of Cologne, said: “We found that the combination of aztreonam and EGCG was significantly more effective at reducing P. aeruginosa numbers than either agent alone.“ This synergistic activity was also confirmed in vivo using Galleria mellonella (Greater Wax Moth larvae), with survival rates being significantly higher in those treated with the combination than those treated with EGCG or aztreonam alone. Furthermore, minimal to no toxicity was observed in human skin cells and in Galleria mellonella larvae.
Lead author Dr Jonathan Betts, Senior Research Fellow in the School of Veterinary Medicine at the University of Surrey, said: “Natural products such as EGCG, used in combination with currently licenced antibiotics, may be a way of improving their effectiveness and clinically useful lifespan.” Further development of these alternatives to antibiotics may allow them to be used in clinical settings in the future.
This research was carried out in partnership with the University of Surrey and Public Health England.