by Dan Gunderson, Minnesota Public Radio
October 10, 2013
FARGO, N.D. — Researchers at North Dakota State University have discovered a way to make the E. coli bacteria less dangerous to human health, a finding that could improve safety in food and medical devices.
Bacteria can make people sick, and the organisms are much more dangerous when they form a social network called a biofilm that allows them to communicate and protect each other. According to the National Institutes of Health, biofilms cause 60 to 80 percent of microbial infections.
E. coli could soon become less of a threat thanks to the work of Meredith Irsfeld, a graduate student researcher at NDSU who fed bacteria a neurotransmitter found in the brain called phenylethylamine, or PEA. When the E. coli bacteria consumed PEA, they stopped growing the hair-like appendages called flagella they need to move and attach to surfaces and each other.
If bacteria can't form biofilm, they are less dangerous and more easily controlled with antibiotics.
The discovery represents a significant advancement because defeating biofilm would make it difficult for bacterial to link in ways that make them more potent and difficult to kill.
"They form on surfaces. They glue themselves to the surface, they glue themselves to each other and after that they are very difficult to remove," said Birgit Pruess, an associate professor in the Veterinary and Microbiological Sciences Department at NDSU.
"Antibiotics don't get to them," said Pruess, who has spent years looking for ways to defeat biofilm. "The immune system of the human host doesn't either."
PEA, which also is sold as a health food supplement alleged to enhance weight loss and fight depression, could be a key to fighting E. coli because it does not allow bacterial connections, Irsfeld said.
"The gene that produces flagella is brought down immensely," she said. "So it's not able to form that initial attachment. And that initial attachment is needed for biofilm to even begin."
A lot of researchers are now looking at ways to control bacteria by suppressing genes to change behavior but the NDSU lab is the first to try using PEA, Pruess said.
Because this approach changes the bacteria rather than killing them, it will take longer for the bacteria to adapt and become resistant, she said.
Pruess received a $358,750 NIH grant for the research. She also received funding from the North Dakota Beef Commission, and the State of North Dakota.
More studies are needed to fully understand why this specific gene is suppressed, but researchers are already moving forward on practical uses for what they've learned.
NDSU researchers will look for ways to embed PEA in medical devices to prevent biofilm formation.
Biofilms are a big problem for medical devices because they can form on hip or knee implants, pacemakers or catheters used in dialysis or cancer treatments. That can cause serious infections that resist antibiotic treatment.
Pruess said there are also many ideas to use the discovery to improve food safety.
"Someone said, 'Why don't you fit it in a little bottle and sell it in the store so people can use it in their own refrigerators?'" she said. "We just gave a seminar and someone said, 'Why don't you put it in the package material for the beef?' So there is right now a lot of ideas different people bring in about what one could do with this."
Pruess thinks a ready-to-use material could be developed in two or three years. Government approval might take much longer.
Because of the federal government shutdown, however, the next phase of research is on hold.
Source:
http://minnesota.publicradio.org/display/web/2013/10/10/ndsu-discovery-defeats-biofilm
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