In the first large-scale screening of its kind, scientists profiled almost 3000 drug combinations on three different disease-causing bacteria. The research was led by European Molecular Biology Laboratory (EMBL) group leader Nassos Typas and published in the journal, Nature, last Wednesday.

This study is important because overuse and misuse of antibiotics has led to the creation of organisms that are resistant to many antibiotics. And, although effective against resistance, treatments with combinations of antibiotics have gone largely unexplored and are rarely used in practices. In this study, the team systematically studied the effects of antibiotics paired with each other and paired with other drugs as well as food additives in different species.

Of the various combinations tried, many lessened the antibiotics outcome. Yet, there were over 500 drug combinations that improved the results, not just in common strains of bacteria but with multi-drug resistant bacteria. According to the study, “ A selection of these positive pairings was also tested in multi-drug resistant bacteria, isolated from infected hospital patients, and were found to improve antibiotic effects. “More than 70 percent of the dual drug combinations are species specific, meaning they are designed to target a specific of bacterium, while 20 percent display strain specificity. Researches said both reveal a large potential for narrow-spectrum therapies.

Vanillin

Interestingly, Vanillin, which gives vanilla its distinctive taste, was pared with one particular antibiotic known as spectinomycin which was originally developed in the early-1960s for treating gonorrhea but is rarely used today because bacterial resistance developed. However, in combination with vanillin it could become clinically relevant once again and used for other disease-causing microbes. “Of the combinations tested, this was one of the most effective and promising synergies we identified,” says Ana Rita Brochado, first author on the paper and research scientist at EMBL. “Pairings such as this could extend the arsenal of weapons in the war against antibiotic resistance.”

This combination helped the antibiotic enter bacterial cells and inhibit their growth. On the other hand, the researchers found that vanillin lessened the effect of many other types of antibiotics, as aspirin does as well.

Damage control

Combinations of drugs that decrease the effect of antibiotics could also be beneficial to human health because, says researcher, Nassos Typas, “Antibiotics can lead to collateral damage and side effects because they target healthy bacteria as well. But the effects of these drug combinations are highly selective, and often only affect a few bacterial species. In the future, we could use drug combinations to selectively prevent the harmful effects of antibiotics on healthy bacteria. This would also decrease antibiotic resistance development, as healthy bacteria would not be put under pressure to evolve antibiotic resistance, which can later be transferred to dangerous bacteria.”

While the compounds tested by the researchers are known to be safe for humans, trials will still, be needed to test the efficacy of certain drug combinations.


Research

1. Combining antibiotics alters effectiveness, study says. UPI. July 5, 2018
https://www.upi.com/Health_News/2018/07/05/Combining-antibiotics-alters-effectiveness-study-says/2901530799691/