BRILLI-ANT

Professor Matt Hutchings

Professor of Molecular Microbiology

University of East Anglia

One of the biggest risks to human health today is antimicrobial resistance (AMR), where disease-causing bacteria and fungi become resistant to the antibiotics used in human medicine: UEA researchers are searching in unusual places for new antibiotics to address this crisis.

So, how exactly does AMR occur?

Most of the antibiotics currently in clinical use are derived from a group of bacteria called actinomycetes, which were isolated from soil between 40-80 years ago.

Ant colony

The inappropriate use of these antibiotics in medicine and agriculture over the last seven decades has led to antimicrobial resistance (AMR), whereby disease-causing bacteria and fungi have become resistant to one or more types of antibiotics.

The increase in antibiotic resistant infections means that in 10 - 15 years routine medical procedures like surgery and chemotherapy, where patients are given antibiotics as a matter of course, could become impossible. By 2050, drug resistant infections are predicted to become the biggest cause of human death.

UEA scientists are trying to raise awareness about the problem of antimicrobial resistance and find solutions to the AMR crisis.

ANT-IBIOTICS

U

EA researchers have certainly taken an interesting approach and the unusual places where they are hunting for new antibiotics are particularly intriguing.

Ants Ants Ants Ants

Our scientists and their collaborators at the John Innes Centre have been looking at fungus-growing ants to try and learn the ways in which these fascinating creatures have been using antibiotics for millions of years. Their research focusses on both African Tetraponera plant ants and South American attine ants. Attine ants are ancient farmers that have been growing their own food for over 50 million years. They grow a symbiotic fungus as food and cultivate it in underground chambers known as fungus gardens. This fungus provides the only food source for their larvae and queen, so it’s crucial for the survival of the entire ant colony.

Attine ants are ancient farmers that have been growing their own food - and using antibiotics - for over 50 million years.

Ant's head

But which is the most highly evolved ant of all?

They’re known as leafcutter ants. Their name comes from their ability to cut leaves from the rainforest canopy, carry them back to their underground nests, and then chew them up and feed them to their symbiotic fungus.

Ant's head

They then use their own faecal droplets as manure to help grow the fungus. This ancient form of agriculture could potentially help humans more than we ever realised.

Learning From Ants

Life cycle of a Leafcutter Ant

Callows (new worker ants) get inoculated with filamentous Pseudonocardia bacteria within 24 hours and they bloom all over their bodies - they are visible to the eye as white covering.

Lifecycle of leafcutter ants

Professor Matt Hutchings, leader of the research team at UEA, believes leafcutter ants could teach humans a lot about antibiotic use because they’ve been using antibiotics for millions of years without any issue of AMR. The ants are incredibly resourceful in the way 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.

Bioassay plate showing that the ant-colony-killing Escovopsis fungus is unable to grow near the white ‘good’ bacteria which is excreting antifungal compounds
Bioassay plates Bioassay plate

Ant Diagram

Drag the slider below to take a look around a worker ant

FIGHTING THE
SUPERBUGS

UEA and Prof Barrie Wilkinson at the John Innes Centre (JIC) have also carried out joint research into the African fungus-growing plant-ant Tetraponera penzigi. They found a new member of the Streptomyces bacteria family in these ants’ nests which produces a new group of antibiotics that are potent against antibiotic-resistant ‘superbugs’ like MRSA and vancomycin resistant enterococci (VRE). These are both classed as high priority for the development of new antibiotics by the World Health Organisation.

This new species has been named Steptomyces formicae, and they have called the antibiotics ‘formicamycins’– after the Latin Formica, meaning ant.

Prof Hutchings said: “We have been exploring the chemical ecology of the symbioses formed between antibiotic-producing bacteria and fungus-growing insects to better understand how these associations are formed and explore them as a new source of anti-infective drugs.


“Kenyan plant-ants live in symbiosis with thorny acacia trees. They live and breed in domatia - which are hollowed out structures which the plant evolved to house them. The ants live and grow a food fungus inside the domatiaand in return they protect the plants from large herbivores including elephants, which won't eat plants covered in ants.”

“We tested our new antibiotics against superbugs like MRSA and discovered they don’t become resistant, giving us a potent new weapon in the fight against AMR.”

Professor Matt Hutchings

Hutchings said: “We tested formicamycins against clinical isolates of MRSA and VRE and found that they are very potent inhibitors of these organisms. More importantly, when we grow VRE and MRSA in sub inhibitory concentrations for long periods of time they did not evolve resistance to the formicamycins.”

Prof Wilkinson from JIC commented: “Our findings highlight the importance of searching as-yet under-explored environments, which, when combined with recent advances in genome sequencing and editing, enables the discovery of new species making natural product antibiotics which could prove invaluable in the fight against AMR.”

Antibiotics of the Future

UEA researchers continue to engage widely with the general public and the media to try and tackle AMR through promoting public awareness and encouraging better antibiotic stewardship in the future.

It is clear we must learn from the mistakes of the past and use the next generation of antimicrobials more wisely in order to prevent a return to a pre-antibiotic era. UEA researchers are also continuing the search for new antibiotics in under explored environments – the question is, what will they find next?