The field of microbiology has developed expansively such that a wide array of information on microorganisms has allowed for us to learn how to counteract the harmful ones. The manufacture of antibiotics has contributed enormously to combatting diseases caused by these microscopic living things that were otherwise incurable in the past. However, antibiotics have always been characterised by the downside of creating resistant bacteria. The large-scale consumption of antibiotics ultimately exerts a pressure on the bacteria such that they grow resistant to the pills and, after some time, the antibiotics are no more effective. Fortunately though, a recent scientific work might have tackled this problem.
A new class of potent antibiotics, known as teixobactin, has been discovered that is able to destroy a range of bacteria without leading the latter to develop resistance. Not only can it handle a number of different microorganisms but it also comes without the resistance trigger. It was found through the screening of 10 000 strains of bacteria harvested from the soil.
Antibiotics are generated from substances extracted from some bacteria. The latter are analysed to detect any chemical or cell apparatus or mechanism that is successful at killing other bacteria – those which are harmful to humans. This strategy would work relatively well in curbing diseases, but the bacteria have gained the upper hand in most cases. They have managed to undergo mutations that change their sensitivity to the antibiotics. Furthermore, the engineering of new antibiotics is not proceeding at the ideal pace. The two-sided problem appears to be increasingly threatening to modern medicine, and infections might soon get out of hand.
The limitations also include the untapped resources represented by bacteria that have not been cultured. These make up 99 %; only 1 % has been properly grown in labs. The bulk of these bacteria have not been grown because of the obstacles in culturing them in laboratories while they might be holding invaluable secrets to new antibiotics.
The focus on the scientists of the new study was on this group of bacteria – the uncultured ones. They have managed to devise a way to explore them by way of a tiny device known as iChip. The iChip consists of hundreds of chambers in which a cell of a different bacterium is added. The iChip is then placed under the soil. The soil being their ideal environment allows for the bacteria to naturally grow into colonies. Thereafter, they are placed onto Petri dishes and overlaid with an upper layer of bacteria called Staph. The different colonies might then manufacture antibiotics to prevent the Staph from growing – this is indicated by an empty zone in the Petri dish.
10 000 bacteria were thus screened in this manner to find out which creates a potent antibiotic against the Staph. This was how the teixobactin was demonstrated to be effective against bacterial strains causing pneumonia, tuberculosis, and other diseases, when tests were done on mice. Furthermore, no side effect was recorded.
However, one type of bacteria seemed to remain immune to teixobactin: the Gram-negative bacteria. The latter are already a challenge to existing antibiotics.
They are known to be responsible for diseases like cholera, gonorrhea together with some food-borne diseases.
What makes teixobactin so special?
The researchers stated that the mechanism by which teixobactin kills bacteria suggests that resistant strains would only take decades to develop. The chemical binds to several targets and breaks down the cell walls of the bacteria. This killing strategy would be difficult for the bacteria to counteract, according to the scientists.
Clinical trials yet?
It has not yet been determined whether it is completely safe to humans though. Tests carried out on mice so far have proved to be positive enough. The next steps will include more experimenting on animals before clinical testing is done; the delay for the final phase would happen in two years if the procedures go on smoothly, and it would take another two to three years for it to be complete.