Issue date: 18 October 2004

ISSUE DATE: 18/10/04

Scientists at the University of the West of England are studying the slippery mucus on the skin of rainbow trout and other freshwater fish as a possible source of new medicines to fight infectious diseases.

The research, which is still at an early stage uses the technology of bioluminescence to examine the antibacterial properties of the mucus.

Dr Carolyn Paul, who is conducting the research in collaboration with Dr Chris Bolton and Dr Vyv Salisbury, explains, “Anglers, cooks and anyone cleaning up mess in their kitchen know how difficult it is to hold onto fresh slippery fish like rainbow trout. Trout are tricky to grasp because of the thick mucus they secrete from their skin. This slime helps them in many ways, and contains important chemicals which let them fight off bacteria living in the river.”

Dr Chris Bolton suggested, as a result of his interest in angling, that fish may have protective chemicals in their body slime. This idea seems to be correct. The scientists are looking at the possibility that the same chemicals might be used to help people fight off infectious disease-causing bacteria including food poisoning culprits E.coli and Salmonella, and the microbe Pseudomonas which affects the lungs of vulnerable cystic fibrosis patients.

“Extracts from the trout mucus have already been shown to prevent growth and slow down the metabolic activity of some of these types of infectious bacteria. Our work is at a very early stage but if we can purify and produce these chemicals commercially, they may give us a new type of antibiotic, badly needed in view of the growing menace of antibiotic-resistant bacteria,” says Dr Paul.

Dr Vyv Salisbury explains how they are using bioluminescence in the research, “To see if the fish slime has an antibiotic effect, the team at UWE are using genetically modified disease-causing bacteria, which glow in the dark when they are active and stop glowing when they are killed. The drop in the light given off by these bioluminescent reporter bacteria, when they are put on the fish slime, is a very effective way of measuring the antibacterial action of the slime.”

Dr Salisbury is also working on an important research project funded by the European Commission, entitled BUGDEATH, which uses bioluminescence to help predict how well pasteurisation works to reduce bacteria on the surface of food.


Editor’s notes

The initial research on fish slime results from original discussions between Dr Chris Bolton and Dr Carolyn Paul and formed part of a final year student project by Hayley Staple supervised by Dr Paul. Dr Vyv Salisbury presented the research: ‘Antimicrobial properties of Oncorhynchus mykiss (rainbow trout) epidermal mucus extracts’ on Monday 6 and Tuesday 7 September 2004 in the Plenary poster session of the 155th Meeting of the Society for General Microbiology at Trinity College, Dublin (6 – 9 September 2004). For full details see:

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