Ants found to use multiple antibiotics as weed killers
8 September 2010
Research led by Dr Matt Hutchings at the University of East Anglia and involving The Genome Analysis Centre and the John Innes Centre, both BBSRC Institutes, shows that ants use the antibiotics to inhibit the growth of unwanted fungi and bacteria in their fungus cultures which they use to feed their larvae and queen.
These antibiotics are produced by actinomycete bacteria that live on the ants in a mutual symbiosis.
Although these ants have been studied for more than 100 years this is the first demonstration that a single ant colony uses multiple antibiotics and is reminiscent of the use of multidrug therapy to treat infections in humans.
The work, which was funded by the Medical Research Council, has also identified a new antibiotic that could be used to treat fungal infections. Fungiculture in the insect world is practiced by ants, termites, beetles and gall midges.
Dr Hutchings' research investigates the Acromyrmex octospinosus leaf cutter ant, endemic in South and Central America and the southern US. These ants form the largest and most complex animal societies on earth with colonies of up to several million individuals. The garden worker ants researched were collected from three colonies in Trinidad and Tobago.
Dr Hutchings said: "This was really a fun project which started with a PhD student, Joerg Barke, streaking leaf-cutting ants onto agar plates to isolate antibiotic producing bacteria. Joerg, with his colleagues Ryan Seipke and Sabine Gruschow, really pushed this project forwards and made these major discoveries. They really deserve most of the credit for this work."
The genomes of some of these antibiotic-producing bacteria were then sequenced by researchers at The Genome Analysis Centre (TGAC). They scanned the entire genome and found areas that showed high similarity to genes involved in the biosynthesis of a previously identified antifungal compound. Further genome analysis by TGAC researchers established that the bacteria contain a gene cluster highly likely to produce a novel antifungal compound related to the clinically-important antifungal, nystatin.
"We're excited about the potential of these ants and other insects to provide us with new antibiotics for medical use," said Dr Hutchings. "It's also very exciting that ants not only evolved agriculture before humans but also combination therapy with natural antibiotics. Humans are just starting to realise that this is one way to slow down the rise of drug resistant bacteria - the so called superbugs."
TGAC is a BBSRC national centre for genomics and bioinformatics. It that addresses problems in agriculture, sustainable energy, food and nutrition, through novel approaches in genomics technology and data analysis. Dr Hutchings' group carried out the project through TGAC's Capacity and Capability Challenge (CCC), an early access research programme that gives UK researchers the opportunity to engage with TGAC in innovative sequencing and bioinformatics projects. The CCC is delivering a series of projects addressing not only biological research problems, but also technical challenges to sequencing and associated informatics.
The paper, entitled 'A mixed community of actinomycetes produce multiple antibiotics for the fungus farming ant Acromyrmex octospinosus' is published in BMC Biology.
BBSRC is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £470M in a wide range of research that makes a significant contribution to the quality of life in the UK and beyond and supports a number of important industrial stakeholders, including the agriculture, food, chemical, healthcare and pharmaceutical sectors.
BBSRC provides institute strategic research grants to the following:
- The Babraham Institute
- Institute for Animal Health
- Institute of Biological, Environmental and Rural Sciences (Aberystwyth University)
- Institute of Food Research
- John Innes Centre
- The Genome Analysis Centre
- The Roslin Institute (University of Edinburgh)
- Rothamsted Research
The Institutes conduct long-term, mission-oriented research using specialist facilities. They have strong interactions with industry, Government departments and other end-users of their research.