In a new study, scientists discovered a previously unencountered antibiotic. Preliminary research results showed that it could be particularly useful in treating drug-resistant infections, writes Focus.
Chemists have announced the discovery of the first representative of a new promising class of antibiotics — the discovery came as a surprise, as the authors of the study did not set out to search for new drugs, writes Live Science.
Discovery of a New Generation Antibiotic
According to the team, the new antibiotic demonstrates promising activity against drug-resistant infections, including:
- methicillin-resistant Staphylococcus aureus (MRSA);
- Enterococcus faecium — microbes that cause resistant infections.
According to the lead authors of the study, chemists Lon Alhalaf and Greg Challis, they reported the discovery of the new molecule in their article published in the Journal of the American Chemical Society. However, the team's original goal was not to discover new drugs — in fact, the scientists were studying how the well-known antibiotic, methylenomycin A, is synthesized by the soil bacterium Streptomyces coelicolor.
It is known that plants and microorganisms produce a multitude of complex compounds called secondary metabolites. Many of them actually possess beneficial healing properties for humans. This is why understanding how these compounds are synthesized in these organisms and how they interact with human cells can actually help scientists develop effective drugs based on these natural products.
According to the scientists, the programs for producing these various molecules are stored in specific groups of genes known as "biosynthetic gene clusters." In their research, chemists removed individual genes from these clusters, allowing them to eliminate specific enzymes involved in the synthesis of methylenomycin A. This method allowed scientists to halt the reaction sequence at key points for more detailed study, as well as to selectively isolate previously unobserved intermediate compounds formed during this process.
As a result, the scientists were able to isolate two previously unencountered molecules, which they named pre-methylenomycin C and pre-methylenomycin C lactone. The scientists also used different methods, which allowed them to investigate the biological activity of the molecules against a range of bacterial strains.
Effectiveness of the New Antibiotic
According to Challis and Alhalaf, pre-methylenomycin C lactone turned out to be incredibly promising — it is active against a number of gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and a multi-resistant strain of Enterococcus faecium. Moreover, the results indicate that the new antibiotic is 100 times more effective at killing drug-resistant bacteria than the original antibiotic. Even more importantly, the new antibiotic does not cause the development of antibiotic resistance in the treated strains.
It is worth noting that repeated exposure to antibiotics can provoke the development of protective mechanisms in some bacteria, ultimately leading to the development of resistance, which makes treating infections extremely difficult.
During the study, the scientists conducted a 28-day experiment in which E. faecium bacteria were exposed to increasing concentrations of pre-methylenomycin C lactone, creating ideal conditions for the development of resistance. However, as a result, the scientists observed no changes in the minimum concentration of the drug required to achieve a visible effect.
The scientists intend to continue their research to turn the discovered antibiotic into a drug that remains in the body long enough, is non-toxic to humans, and is not prone to developing resistance. Additionally, the scientists aim to expand the number of bacterial strains that the antibiotic can affect.
