http://www.digitaljournal.com/tech-and-science/science/super-tough-antibiotic-to-fight-superbugs/article/493893

Super-tough antibiotic to fight superbugs

Posted May 30, 2017 by Tim Sandle
Microbiologists have managed to ‘re-engineer’ an existing antibiotic so that it can take on one of the most threatening ‘superbugs’: the genera of vancomycin-resistant enterococci.
Petri dish containing CRE
Petri dish containing CRE
CDC
The antibiotic that has been re-designed is vancomycin and the alteration makes the new version far more potent than the exiting drug. Vancomycin is an antibiotic intended to treat a number of bacterial infections. The drug is administered intravenously for complicated skin infections, bloodstream infections, endocarditis, bone and joint infections, and meningitis.
The re-design of the antibiotic comes from The Scripps Research Institute. The organisms that the drug is aimed at are vancomycin-resistant enterococci. The increasing emergence of vancomycin-resistant enterococci has caused concerns for health institutes and hospitals worldwide. Infection is more likely in people with chronic diseases like diabetes or patients who have recently received antibiotics. The mechanism of resistance to vancomycin found in enterococcus involves the alteration of the way the organism forms its cell wall (made up of a material called peptidoglycan). To become vancomycin-resistant, vancomycin-sensitive enterococci typically obtain new DNA from mutated cells.
Key to the re-design is to enable vancomycin to tackle bacteria in different ways. By having more than one mechanism of attack this means that it is harder for bacteria to develop resistance. The lead researcher Dr Dale Boger told BBC News: "We made one change to the molecule vancomycin that overcomes what is the present resistance to vancomycin. And then we added to the molecule, two small changes that built into the molecule, two additional ways in which it can kill bacteria.”
This means, the researcher explains the antimicrobial drug has three different mechanisms through which it can kill bacteria. This means that bacterial resistance to the antibiotic would be relatively difficult.
The modified antibiotic arose from Dr. Boger's work in total synthesis of complex organic molecules. Under laboratory conditions the antibiotic killed samples of vancomycin-resistant enterococci. This continued for fifty cycles, after which the study was halted.
However, it is important to note, however, that the antibiotic has yet to be tested on animals. Moreover, it remains someway away from a human trial (the scientists behind the development are estimating five years). What is of interest is the potential of the re-designed antibiotic.
The research has been published in the journal PNAS. The research paper is titled “Peripheral modifications of [Ψ[CH2NH]Tpg4]vancomycin with added synergistic mechanisms of action provide durable and potent antibiotics.”