Thursday 15 November, 2001
Killer sweat
The inability to smell sweetly is often frowned upon in society, but new research has found that not everything about body odour is bad.
Science In Action reports on the ability of sweat to keep skin-dwelling bacteria at bay.
Scientists in Germany recently reported the discovery of a natural antibiotic in human sweat.
They’ve found that when we sweat, our skin produces a protein which can kill a range of bacteria. Known as Dermcidin, this protein could potentially mark a route to a new kind of antibacterial drug.
Lead researcher Birgit Schittek from Eberhard-Karls University in Tübingen, explains the structure of the protein that can kill microbes such as E.coli and the yeast, Candida Albicans:
‘It is a long protein which is then cut into pieces. One of these pieces is anti-microbial; it is toxic to the micro-organism and this is found in sweat. It is cut in pieces otherwise it would be toxic for the cell.’
When does it work?
Whilst sweat glands constantly secrete the natural agent, the researchers found that as bacteria thrives in warm, moist conditions, the body is more likely to make use of this natural antibacterial when the temperature rises. Schittek explains:
‘You sweat when you are hot or in action and these are optimum conditions for bacteria to grow.’
| ‘We have to fight against these micro- organisms and this is the first protein that we have found that is constantly produced by skin cells.’ |
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Scientists have previously studied the production of natural antibodies when the skin is broken.
Reporting in the journal Nature, Keith Holland, a skin specialist from the University of Leeds, UK, explains how the natural antibodies in sweat could be important in protecting wounds from bacterial infection. He comments:
‘Skin crawls with hundreds of thousands of microbes… natural antibiotics in sweat may be particularly important when we damage the skin, stopping resident bacteria getting inside to cause infection.’
How does it work?
Currently the scientists are unsure as to how Dermcidin actually disables the bacteria. Schittek explains:
‘Other known anti-microbial proteins punch holes into the membrane of the bacteria. We don’t know from our protein what it is doing. Is it working the same way or does it bind to another protein? We will test in future whether bacteria can get resistant to this protein.’
Once they have cracked the protein’s code it is hoped that it could be used in anti-bacterial products, but, as Schittek explains, there is still vital research ahead:
| What is Staphylococus aureus? | |
This is a bacteria that causes illnesses ranging from minor skin infections and abscesses to life-threatening diseases such as severe pneumonia, meningitis, bone and joint infections, and infections of the heart and bloodstream. |
‘We have to test whether this protein kills other bacteria. One of those that we tested already is Staphylococus aureus, but what would be interesting would be to test mighty resistant strains which are not killed by usual antibiotics.’
|  |  | | | Sweating |  |
| | On average humans loose over a litre of sweat per day.
Sweat is actually odourless. The smell comes from products made when bacteria feed on the sweat from the armpits and groins. |
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