Bacteria use antibiotics as a weapon and even produce more antibiotics if there are competing strains nearby. This is a fundamental insight that can help find new antibiotics. Leiden scientists Daniel Rozen and Gilles van Wezel published their research results in the authoritative Proceedings of the National Academy of Sciences USA on 28 July 2015.
Antibiotics as weapons in nature
The Leiden scientists discovered that in nature, too, antibiotics act as a weapon against rival bacteria. This seems logical, but remains controversial, because the concentrations in the soil appear to be far too low to act as a weapon against other bacteria. Rozen, Van Wezel and colleagues made the discovery by measuring the activity of thirteen strains of the antibiotic-producing bacterium Streptomyces. They looked at how strains behaved in nutrient-rich as well as nutrient-poor soil. They found that in soil with few nutrients and competing bacteria nearby the Streptomycetes start to produce more antibiotics in order to protect the food sources available. Computer simulations showed how the strains enter into a lot of 'social interaction' in a nutrient-rich environment, allowing the exchange of genetic material and the creation of new bacterial variants.
Apart from the fundamental question, it also offers important new insights into the search for new antibiotics, say Rozen and Van Wezel. 'The Streptomyces bacteria are able to produce the antibiotics we seek, but they will not do this automatically. You have to, as it were, awaken the antibiotics in the bacteria by stimulating them in the right way. This research shows how the bacteria can be stimulated to produce antibiotics by growing them in the presence of competing strains.'
Antibiotics important for combating diseases
Antibiotics are an important substance for combating diseases, but pathogens are becoming increasingly resistant to existing antibiotics. The research into new antibiotics carried out by Gilles van Wezel, Professor of Molecular Biotechnology, is linked to the research at Leiden University which is aimed at developing new drugs. For more information, please consult the research dossier on Effective Drug Development.
Explore further: Antibiotic resistance is a gut reaction
PNAS Early Edition Monica I. Abrudan, DOI: 10.1073/pnas.1504076112