Teixobactin: A Super Drug, Or A Super Bug?

Jan 17, 2015 By Radhika, Guest Writer
Radhika's picture

When it was discovered, penicillin was considered a “miracle drug.” It was the first true antibiotic, with the amazing ability to kill bacteria and cure patients suffering from a wide variety of diseases.

The story of penicillin and other antibiotics shows that even miracles have downsides. With over-use of these antibiotics, we are now seeing a rise in antibiotic-resistant bacteria. 

The rise of these "superbugs" is forcing scientists to constantly develop new drugs. Recently, scientists at Northeastern University used a new method of creating antibiotics, developing a promising new drug.

Teixobactin: A Miracle

The new antibiotic, teixobactin, has been very successful in the early stages of development. So how does it work?

It takes advantage of the cell wall of the bacteria, which is made of a type of lipid (or fat) known as peptidoglycan. Teixobactin sticks to these molecules, preventing them from binding together—therefore preventing the cell wall from forming. Most importantly, because animal cells (the type of cells in human bodies) don’t have cell walls, teixobactin will essentially have no effect on us.

Early tests on mice infected with MRSA (a type of bacteria that is extremely drug-resistant) have shown a lot of promise. The drug wiped out the MRSA without harming the mice. Hopefully, the same results will be seen in humans.

Does It Work On All Bacteria?

Teixobactin’s one limitation is its inability to affect gram-negative bacteria. There are two main groups of bacteria: gram-positive and gram-negative.

Gram-negative bacteria such as E. coli or Salmonella have an outer membrane that surrounds the cell wall, preventing the drug from interacting with the peptidoglycan that makes up the cell wall. Gram-positive bacteria such as MRSA or Streptococcus do not have this outer membrane, which leaves their cell walls vulnerable.

The Discovery Of Teixobactin

While teixobactin is certainly an exciting development in the field of medicinal chemistry, the way in which it was discovered is even more exciting.

Most drugs are based on what scientists find in nature, and antibiotics are no different. For example, before humans used it, penicillin was originally produced by fungi to kill bacteria. So, in order to develop new antibiotics, scientists analyze microorganisms in the soil. However, only 1% of bacteria in the soil can be grown in laboratory conditions; most die once they are removed from their environment.

Enter the iChip, a simple, yet revolutionary technique of looking at that other 99%.

The iChip is a network of microscopic wells that are covered by a permeable membrane. By placing a single microbe in each well, the microbes can be isolated and observed while still living in an environment in which they can thrive. Using the iChip, scientists have been able to observe 10,000 new bacteria and all the chemicals that they produce. Teixobactin was one of these chemicals.

How much more has been left undiscovered simply because we were unable to analyze the dirt under our feet? Only time will tell.

Courtesy: BBC, Nature