Scientists discovering new antibiotics in ants, stick insects and moths
NewsTuesday 03 September 2013
Scientists have been investigating new sources of antibiotics, which some people may find surprising. These sources include ants, stick insects, soil and potatoes.
The antibiotic research was carried out at the John Innes Centre (JIC) as well as the University of East Anglia and it featured in the opening episode of the BBC’s regional current affairs series Inside Out last night - 2nd Sept 2013.
Many new antibiotics will be discovered from soil bacteria Actinomycetes, from which half of all antibiotics already in circulation also originate. Professor Mervyn Bibb, a JIC scientist has worked with his colleagues to understand how these bacteria make many of them, and they are now able to manipulate those bacteria to make new antibiotics.
Other scientists at the John Innes Centre and the UEA are investigating more unusual sources such as the surface of leafcutter ant bodies, eucalyptus leaves and even potatoes.
South American leafcutter ants are now living under the spotlight inside the insectary at the centre’s entomology facility. Famous for marching through the rainforest in single file carrying giant parts of leaves, these ants can now be viewed on “ant cam” farming the fungus on which they feed.
Leafcutter ants do not eat the leaf sections they carve from plants, but transport the material underground where it decays and forms a garden of fungus. To protect this food source from unwanted microbes and parasites and to regulate the growth of the fungus, the ants also cultivate antibiotic-producing bacteria on their own bodies.
One of the antibiotics that has already been discovered on these ants is related to an antifungal that is used in modern medicine. It is also 300 times more soluble in water making it potentially more useful. Dr Matt Hutchings from UEA hopes that studying the ants will uncover completely new antibiotics too.
The insectary is also hosting the Giant Lime Green stick insect and the Death’s Head Hawkmoth. In the wild, the stick insect feeds primarily on eucalyptus, and the hawkmoth primarily on potato. These plant foods both contain toxins that may have antibacterial properties. The guts of these insects have been found to contain antibiotic-resistant bacteria, so the scientists know they have been exposed to antibiotics through their food.
“This research is at the very early stage but it is exciting to investigate new solutions to the increasing problem of antibiotic resistance,” said Katarzyna Ignasiak who is carrying out the work with insects at the John Innes Centre.
The work with soil bacteria is at a more advanced stage and research carried out in Prof Bibb’s laboratory has contributed to the progression of an antibiotic towards Phase II clinical trials by the JIC spin-out company Novacta Biosystems.
Picture: Clinton and Charles Robertson