Antibiotic resistance is a global emergency, one that we have very few effective weapons against. Potential hopes are arising in the form of new synthetic drugs that are able to “disable” these so-called superbugs, but so far, the war is definitely not favoring our own species.
As a new study in Scientific Reports reveals, though, we may have been overlooking the potential of pre-existing antibiotics for some time. Based on very precise laboratory observations, it appears that certain varieties are able to literally tear certain bacteria apart using sheer mechanical force – and this could be harnessed to turn the tide of the fight against superbugs.
“Antibiotics have 'keys' that fit 'locks' on bacterial cell surfaces, allowing them to latch on. When a bacterium becomes resistant to a drug, it effectively changes the locks so the key won't fit anymore,” lead author Joseph Ndieyira, a research associate at University College London (UCL), said in a statement.
“Incredibly, we found that certain antibiotics can still 'force' the lock, allowing them to bind to and kill resistant bacteria because they are able to push hard enough,” he added. “In fact, some of them were so strong they tore the door off its hinges, killing the bacteria instantly!”
Antibiotics work in a range of ways. Some break down the cell walls of the bacteria, which causes them to burst. Others corrupt a bacterium’s ability to synthesize proteins, which are vital for its survival. Certain strains manage to actually break apart their DNA and then prevent them from being repaired.
All of these have been considered to be biochemical processes, not physical ones. However, the team of researchers, led by UCL, used incredibly small sensors to register mechanical changes taking place during bacteria-antibiotic interactions, and found that these microbial warriors were literally punching holes through their targets.
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In fact, the most effective antibiotics were the ones that used their Hulk-like strength to rip the bacteria to shreds – and these were often types that have been underused in the fight against superbugs like MRSA.
For example, vancomycin, a last-resort antibiotic used against MRSA, was found to have a mechanical force strength 11,000 times weaker than oritavancin, another antibiotic used for certain skin infections.
Although the latter is a modified version of the former – meaning they have the same “key” – it appears that vancomycin takes down bacteria using chemical disruption, whereas oritavancin uses brute strength. The difference in effectiveness is startling. Vancomycin takes six to 24 hours to destroy its target, while oritavancin takes just 15 minutes.
Now that this is known, other antibiotics could be modified to give them this ability to mechanically annihilate antibiotic-resistant bacteria. Humanity may have just found the superbug equivalent of a silver bullet.