Antibiotic resistance is one of the greatest challenges of medicine today, threatening mankind with the resurfacing of previously eradicated deadly bacterial diseases. Now, scientists have provided new hope in the battle against antibiotic resistance with the discovery of an antibiotic that can vanquish deadly antibiotic resistant bacteria like MRSA.
Before the discovery of penicillin, the first group of antibiotics able to fight diseases caused by bacterial infections, people would die from what are today known as ‘normal’ every-day infections. Since then, mostly during the 20th century, scientists have discovered and developed a wide-range of antibiotics that have helped in the eradication of deadly bacterial diseases, such as tuberculosis. However, with the potential of bacteria to become antibiotic resistant, made worse through the misuse of these drugs, doctors are now facing the chilling possibility of eradicated bacterial diseases, resurfacing.
Now, scientists in the team of Kim Lewis of the Northeastern University in Boston, Massachusets, have found an antibiotic that could potentially fight bacteria that have developed resistance to other known antibiotics. They have named this antibiotic teixobactin.
How did researchers discover this ‘new’ antibiotic?
Until today, most known antibiotics have been discovered by scientists looking at bacterial cultures grown in the lab on Petri dishes, and examining their potential to kill other bacteria growing next to them. However, these studies have been limited because scientists were unable to study bacteria that could not survive in the laboratory. This meant that a great number of potential candidates were missed, like microbes that thrive in the soil, due to their inability to adapt to lab conditions.
In this study, using an exciting new device called the iChip, which makes it possible to study bacteria that cannot normally survive under lab conditions, the researchers discovered a type of bacteria, Eleftheria terrae that produce the antibiotic teixobactin. More specifically, using this device the scientists were able to sort a number of different bacterial cells harvested from soil into separate chambers and plant the chamber back into the ground, where various nutrients were able to diffuse into the chambers. This method allowed the bacteria to grow in their natural environment. Using the iChip, the researchers tested if any of the resulting bacterial colonies were able to kill or stop the growth of S. aureus. This study yielded 25 candidates, the most promising of which was teixobactin.
How does teixobactin work and what sets it apart from other antibiotics?
Most known antibiotics work by targeting proteins produced in bacteria, which is a relatively easy mechanism of action for bacteria to overcome and thus become resistant to antibiotics. All they have to do is alter these proteins by producing mutations that won’t allow the drug to act on its target. Teixobactin seems to have a more unique mechanism of action, targeting and binding to lipids in bacterial cell walls. This makes it more difficult for bacteria to become resistant to this molecule, since lipids are important building blocks of bacterial cells walls and altering them would potentially be harmful for the bacteria themselves.
What does this discovery mean for antibiotic resistance?
The discovery of teixobactin by scientists is likely very significant and exciting for the medical community, promising a breakthrough in the fight against antibiotic resistance. Its ability to eliminate deadly bacteria that have developed resistance to most known antibiotics and its potential to prevent further antibiotic resistance, could mean that we would not have to fear the possible resurfacing of previously eradicated bacterial diseases. This discovery and the technology used could open up a whole new world of antibiotics that were previously unknown, just because we did not have the tools required to study these bacterial populations.
However, for every positive there is usually a negative and in the case of teixobactin the negative could be its possible toxicity to eukaryotic cells. Since the products of these bacteria have been a mystery to us so far due to their inability to grow in a lab Petri dish, not much is known about their harmfulness to our organism. With teixobactin, the first step in this direction has already been made, by testing this molecule in mice with promising results. Showing safety in humans would be the next step, a very important one at that too, since it is the most important step of converting a promising antibiotic into a real drug. Until more is known, we will be holding our breaths for the new superdrug that could save the world from the evil powers of antibiotic-resistant bacteria.
Ling, L. L. et al. Nature http://dx.doi.org/10.1038/nature14098 (2015).