Antibiotics 2.0: Re-inventing antibiotic therapies using yesterday's antibiotics for human medicine

From an ever-growing body of science, it is clear that doctors and scientists are finding more antibiotic resistance everywhere they look - from the multidrug resistant bacteria in patients to dairy cow manure and even in the guts of 1-week old infants.

In the literature, a lot has been made of the problem with the antibiotic pipeline. From the 1940s to the 1960s, more than 20 new classes of antibiotic came on the market and since then, there have only been two. Scientists are using every tool at their disposal to try and discover new antibiotics, but success in that endeavor is by no means certain. That's one big reason why -- as I have mentioned before - new drug development doesn't replace the need for better stewardship of the antibiotics we already have, in animal agriculture and human medicine. A new study makes it even more obvious why.

In their Nature Chemical Biology paper, scientists have discovered that a cocktail of three older antibiotics (penicillins, carbapenems and beta lactamase inhibitors), ineffective against MRSA individually, can be as effective as the best current, single drug treatment for MRSA in an animal infection model. Moreover, the MRSA superbugs that were exposed to the 3-drug cocktail over an extended period of time remained sensitive to those antibiotics. Meanwhile, exposing those MRSA bacteria to just one or two antibiotics in combination resulted in formation of bacteria resistant to them.

This study shows that, in an effort to come up with much needed solutions for a serious public health crisis, scientists are using every tool at their disposal - including some older antibiotic classes or subclasses that have fallen out of favor in human medicine as first line treatments for a variety of reasons (such as toxicity or growing resistance) and may be more actively used in animal agriculture (such as penicillins). With an increasingly empty medicine cabinet, scientists are going back to the drawing board and re-considering the use of older antibiotic classes. This study is just one example. A look at the current antibiotic pipeline shows that even a drug from a class of antibiotics, pleuromutilins, only used in animals is currently in clinical trials for human use.

Faced with the threat of antibiotic resistant infections that are difficult to treat, every antibiotic used in either animal agriculture or human medicine takes on increased importance. Using all antibiotics sparingly and responsibly across the board not only keeps antibiotic working in their current forms but may also extend their use as new and effective treatments that are waiting to be discovered.