An ever-increasing number of bacteria can evade the effects of antibiotics, which is considered a serious threat to public health. Researchers are working to develop novel drugs to combat these so-called superbugs, but progress doesn’t seem to be happening fast enough. New work may help in that effort. Scientists at the University of California San Diego have used mathematical modeling and experiments at the lab bench to identify a previously unknown mechanism used by bacteria to survive exposure to antibiotics. Their findings have been reported in Cell, and importantly, their efforts have potentially revealed a way to boost the efficacy of existing antibiotics.
"We have found an unexpected new mechanism that actively growing bacteria utilize to become resilient against antibiotics," said Gürol Süel, a professor of molecular biology at UC San Diego's Division of Biological Sciences. "With this discovery, we can now explore new ways to combat infections that we couldn't have thought of before."
In this study, the scientists found that when bacteria encounter antibiotics, they can alter the level of magnesium ions that they absorb. That stabilizes structures called ribosomes, which are complexes that generate proteins in bacteria (in eukaryotes, ribosomes are protein-generating organelles).
The scientists looked closely at the flow of magnesium ions across the bacterial cell membrane, called a membrane potential, and how it related to ribosomal activity. Many different ions play important biological roles, so bacterial cells must control their flow in order to modulate the processes within. The research team’s work "reveals how these ancient and fundamental cellular processes that are essential for life are interacting with each other," said Süel. Bacteria use magnesium ions in their effort to defend against antibiotics. Disrupting their ability to take magnesium up can have an important impact.
"Antibiotic resistance is a major public threat to our health," said Süel. "The number of drugs coming onto the market is not keeping up with the ability of bacteria to cope with those drugs."
Süel suggested that researchers might be able to make existing antibiotics more effective by tinkering with a bacteria’s ability to absorb magnesium. It might be a shortcut to improved antibiotic potency, without the extensive effort required to bring a new drug to market.
In the video above, Professor Süel discusses his research. You can learn more about the antibiotic resistance crisis from the video below, and about how you can help solve this problem.
Sources: AAAS/Eurekalert! via University of California San Diego, Cell