Teixobactin, the First New Antibiotic Class in 28 Years

In 1928, Alexander Fleming discovered that penicillin has the ability to kill many disease causing bacteria, creating a new kind of medication known as antibiotics. Over the years since then, many variations of penicillin have been discovered and other groups or “classes” of antibiotics have also been found. Each class of antibiotics continues to be refined and new variations of them are found. But since 1987, when the group called “lipopeptides” was found, no new classes of antibiotics have been discovered – until 2015.

The lack of new antibiotics has become problematic because in the meantime, bacteria have been evolving to become resistant to many existing antibiotics. They seem to have an ability to use gene sharing to acquire resistance from other bacteria.

In January of 2015, a new antibiotic called Teixobactin was discovered that can kill MRSA, tuberculosis, strep, anthrax, and C-diff, all of which have developed levels of antibiotic resistance. All of these pathogens are considered to be “gram-positive” and Teixobactin is not effective against gram-negative bacteria, which includes e. coli, cholera, legionella, gonorrhoeae, meningitis, salmonella, yersinia and more.

Teixobactin was discovered using a new method of culturing bacteria, called an isolation chip (ichip). Many species of bacteria won’t grow well in laboratory environments. The ichip allows researchers to seal individual bacteria samples in compartments that are isolated from each other but with access to the nutrient environment found in natural soil through a permeable membrane. The collection of samples is then buried and allowed to grow naturally.

A new antibiotic kills pathogens without detectable resistance – [nature.com]

Abstract
Antibiotic resistance is spreading faster than the introduction of new compounds into clinical practice, causing a public health crisis. Most antibiotics were produced by screening soil microorganisms, but this limited resource of cultivable bacteria was overmined by the 1960s. Synthetic approaches to produce antibiotics have been unable to replace this platform. Uncultured bacteria make up approximately 99% of all species in external environments, and are an untapped source of new antibiotics. We developed several methods to grow uncultured organisms by cultivation in situ or by using specific growth factors. Here we report a new antibiotic that we term teixobactin, discovered in a screen of uncultured bacteria. Teixobactin inhibits cell wall synthesis by binding to a highly conserved motif of lipid II (precursor of peptidoglycan) and lipid III (precursor of cell wall teichoic acid). We did not obtain any mutants of Staphylococcus aureus or Mycobacterium tuberculosis resistant to teixobactin. The properties of this compound suggest a path towards developing antibiotics that are likely to avoid development of resistance.

Teixobactin: A New Antibiotic, and A New Way to Find More – [compoundchem.com]

Teixobactin’s discovery has the potential to be a big deal. If it eventually gets approval for clinical use, it’d become the initial member of the first new major class of antibiotics for at least a decade. A lot of news outlets have touted it as ‘the first new antibiotic for 30 years’; this isn’t strictly the case, however, as new drugs in existing antibiotic classes have been discovered more recently. Whether it’s the first new class of antibiotics for a decade rather depends on how they are defined. The summary graphic below, from a previous post on antibiotics, shows a selection of the main classes and their discovery dates:

iChip: The Future of Antibiotic Discovery – [popsci.com]

But what I found even more interesting than the teixobactin discovery—which other writers have also pointed out—was how the researchers were able to find it. They developed a device called an iChip, which allows scientists to explore the virtually untapped wilds of bacteria for potential antibiotics and other interesting unknown chemicals. And the iChip may be a boon not just for antibiotics discovery, but for finding other types of drugs as well as potential energy sources. Really, any industry that looks to microbes for novel chemicals and inspiration may benefit from the technology.

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