Almost all of the antibiotics currently in clinical use come from a group of bacteria called actinomycetes that were isolated from soil between 40-80 years ago.
Inappropriate use of these antibiotics over the last seven decades has led to widespread antimicrobial resistance (AMR) in which disease-causing bacteria and fungi have become resistant to one or more antibiotics. As part of a 10-point plan, the UK government commissioned O’Neill report on AMR (published May 2016) has recommended stimulating early stage antibiotic discovery efforts and launching a global public awareness campaign to educate everybody about the problem of drug resistance.
Image Caption: Acromyrmex octosponosus worker ants carrying leaf fragments back to the fungus gardens in their underground nests.
Researchers at the UEA, led by Professor Matt Hutchings, are exploring an unusual environmental niche to try and find new antibiotics to tackle AMR and to raise public awareness about this global health crisis.
South American attine ants are ancient farmers that have been growing their own food for more than 50 million years. They are better known as fungus-growing ants because the food that they grow is a symbiotic fungus which they cultivate in underground nest chambers known as fungus gardens. This fungus provides the only food source for their larvae and queen and is vital for the survival of the ant colony. The most highly evolved attines are known as leafcutter ants because they actively cut leaves from the rainforest canopy and carry them back to their underground nests where they chew them up and feed them to their symbiotic fungus.
Image Caption: As above.
They use their own fecal droplets as manure to help the fungus grow. Perhaps even more remarkable than this ancient agriculture is the fact that they use antibiotics to prevent fungal diseases from killing their fungus gardens, which would ultimately kill the whole ant colony. The antibiotics that they use come from actinomycete bacteria, similar to the soil actinomycetes that provided most of the antimicrobial drugs used in human medicine. The worker ants grow the bacteria on the surface of their bodies and feed them through specialised glands. The bacteria have been passed down from generation to generation by the ant queens along with their symbiotic fungus, over tens of millions of years. This is potentially useful to humans because the co-evolved bacteria make antibiotics that are new to science and could eventually be used to treat AMR infections in humans.
Image caption: Actinomycete bacteria called Streptomyces at very high magnification under a scanning electron microscope.
Matt Hutchings believes the leafcutter ant system can also teach humans a lot about antibiotic use because the ants have been using antibiotics for millions of years without any problems of AMR. His research group have engaged widely with the general public at Science Festivals (Royal Society Summer Science 2014, Great British Bioscience Festival 2014, Big Bang 2015, Pint of Science 2016, Norwich Science Festival 2016, Science, Art and Writing Trust workshops) and through the media. They have discovered new antibiotics that kill superbugs like MRSA and VRE (vancomycin resistant enterococci) and multi-drug resistant fungal pathogens of humans. They are currently sequencing genomes of bacteria isolated from the ants to ‘mine’ them for the most novel antimicrobials and they continue to engage widely with the general public and the media to try and tackle AMR through antibiotic discovery and promote public awareness of AMR and encourage better antibiotic stewardship in the future. It is clear we must learn from our mistakes of the past and use the next generation of antimicrobials more wisely if we do not want to return to a pre-antibiotic era.
Explore more UEA research
Searching for the last unicorn
UEA scientist is working on a surprising new way of finding evidence of these elusive animals.
Improving the Atmosphere
Are scientists winning the fight against greenhouse gases and ozone depletion?
Taking the Earth's Temperature
Global temperature data underpins international climate negotiations.