Antibiotic resistant bacteria are one of the biggest threats to global health. As researchers scramble to find solutions, a recent study concludes that a compound found in green tea might boost existing drugs.
Green tea in glass jar
A recent study investigated epigallocatechin, which is a compound in green tea.

Antibiotics have proven essential for treating bacterial infections since doctors first used them in the 1930s.

However, bacteria and fungi are rapidly becoming resistant to the drugs designed to kill them.

As a result, infections caused by drug resistant bacteria can take a lot longer to treat and are sometimes impossible to cure.

In the United States alone, drug resistant bacteria infect at least 2 million people each year, leading to about 23,000 deaths, according to the Centers for Disease Control and Resistance (CDC).

As antibiotic resistant pathogens become increasingly prevalent, researchers are leaving no stone unturned in their search for innovative interventions.

Green tea compound investigated

The most recent study looking for ways to solve the antibiotic resistance crisis investigated green tea. The authors of the study conclude that one particular compound in green tea might bolster failing antibiotics and help them to kill bacteria more efficiently.

The scientists, from the University of Surrey School of Veterinary Medicine in Guildford, United Kingdom, focused on the bacterium Pseudomonas aeruginosa.

This bacterium can cause severe infections to the skin, the blood, and the respiratory and urinary tracts.

The bacteria are growing resistant to many antibiotics and are increasingly difficult to fight. Currently, doctors treat P. aeruginosa infections with a combination of antibiotics.

Green tea contains a compound known as epigallocatechin (EGCG). Medical researchers are interested in this polyphenol for several reasons. For instance, some studies have investigated whether it might treat inflammation and rheumatoid arthritis.

In the latest investigation, researchers combined EGCG with aztreonam, which is an antibiotic commonly used to fight P. aeruginosa. They found that the combination reduced the numbers of P. aeruginosa in laboratory cultures.

The research, which the scientists published in the Journal of Medical Microbiology, also investigated the interaction between EGCG and aztreonam in an animal model. Specifically, they used greater wax moth larvae, which scientists have found to be a useful model for studying antibiotics.

Once again, they found that when they combined EGCG with aztreonam, it was more effective than using the drug or EGCG alone.

The scientists believe that EGCG increases the permeability of the bacterium’s membrane, allowing antibiotics to pass through more easily.

Antibiotic resistance threatens everyone

The World Health Organization (WHO) warns that taking antibiotics when they are not needed — both by humans and livestock — speeds up anti-drug resistance and puts everyone at risk.

It is important to emphasize that it is not a person who becomes resistant, but the bacterium. This means that cures for common infections are under threat.

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.”

Lead author Dr. Jonathan Betts

Dr. Betts continues, “Natural products, such as EGCG, used in combination with currently licensed antibiotics, may be a way of improving their effectiveness and clinically useful lifespan.”

Prof. Roberto La Ragione, Head of the Department of Pathology and Infectious Diseases at the School of Veterinary Medicine at the University of Surrey, explains the potential importance of these results:

“The WHO has listed antibiotic resistant P. 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.”