Research
Beneficial Bacteria
Part 3
Adding Bacteria To Wounds
12-23-2000
How do you prevent wounds becoming infected by dangerous
superbugs? By first adding other bugs, say researchers
in Canada who have found that a cousin of the yogurt
bacterium can stop the growth of harmful bugs.
About 1 per cent of surgical incisions become infected.
If the patient's immune system is weak, or the bacteria
are antibiotic-resistant superbugs, such infections
can kill.
Gregor Reid, a microbiologist at the University of Western
Ontario, wondered if benign bacteria might help. So
he and his colleague Jeffrey Howard coated several small
sheets of silicone with Staphylococcus aureus, a major
cause of hospital infections. Some were also coated
with a strain of the harmless bacterium Lactobacillus
fermentum called RC-14.
The researchers implanted the silicone sheets under
the skin of rats. After a few days, incisions infected
with S. aureus alone were swollen with pus. Those that
received RC-14 as well were clean and healthy.
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The
RC-14 did not kill the S. aureus, but this could actually be good
news. Bacteria become resistant to antibiotics when the non-resistant
members of a colony all die. So they might take longer to develop
resistance if growth is merely inhibited. "I think there is much less
selective pressure with this type of strategy than with antibiotics,"
says Howard.
Howard
has discovered that the active agent secreted by the RC-14 bacteria
is a protein, which may prevent S. aureus from binding to human cells.
In future, the protein could be applied directly to an incision, or
used to coat surgical implants.
Using
live bacteria is also an option, Reid says. "In patients facing death
or amputation it is worthy of investigation."
Jonathan
Knight reporting from the meeting of the American Society for Cell
Biology in San Francisco.
New
Scientist issue: 23/30 December 2000
PLEASE
MENTION NEW SCIENTIST AS THE SOURCE OF THIS STORY AND, IF PUBLISHING
ONLINE, PLEASE CARRY A HYPERLINK TO: www.newscientist.com.
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