A Blast of Cold Plasma Kills Drug-Resistant Bacteria

By Rebecca Boyle Posted 12.15.2010 at 3:57 pm 8 Comments

Plasma Therapy The blood-agar dishes seeded with hemolytic Staphylococcus aureus are shown, plasma treated (left) and untreated control (right). Ermolaeva et. al via PhysOrg

Cold plasma torches could be a new way to treat drug-resistant infections and heal wounds more quickly, according to new research. The plasma interferes with microbial DNA without harming human tissue, scientists say.

A 10-minute treatment with a low-temperature plasma jet killed about 90 percent of drug-resistant bacteria infecting lab rats, according to a study to be published in the January issue of the Journal of Medical Microbiology. It involves a blowtorch spewing ionized gas around 95 degrees to 104 degrees F.

German and Russian researchers say the torch was able to kill 99 percent of the bacteria in a lab-grown biofilm and 90 percent of the bacteria in infected rats. The researchers tried it with Pseudomonas aeruginosa and Staphylococcus aureus, which are both ubiquitous in hospitals and can cause wound infections, especially in people with weakened immune systems. Both are resistant to a wide range of antibiotics.

Svetlana Ermolaeva, who led the research, said plasma therapy kills the bacteria by interfering with their DNA and surface structures — a key in fighting P. aeruginosa and S. aureus, which grow in protective biofilms. Thicker biofilms still show some resistance, but plasma treatment could be a new treatment where traditional antibiotics don’t work.

Plasma is a state of matter involving a collection of free-moving electrons and ions. Usually, high energy is needed to produce it — like a sudden electrical discharge (lightning) or nuclear fusion (a star) — but it’s tricky to make plasmas at atmospheric pressures and room temperatures. Even in cold plasmas, electrons are superheated to thousands of degrees. But by ionizing less of the molecules in a plasma, scientists can produce plasma whose heat is distributed to non-ionized molecules, making it cool — or at least lukewarm — enough to handle.

Eventually, plasma treatments could represent a better option than antibiotics, because microbes will not be able to build up resistance, Ermolaeva said.

[Medical Daily]

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8 Comments

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Loocster05

12/15/10 at 4:09 pm

This is cool, I never really knew much about plasma in the first place I guess now I know a little lol.

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topstop

12/15/10 at 4:54 pm

Sounds like a "Dentron Biogun" that has been comercialy available in the UK for at least 15 years. So whats new?

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awjanua

12/15/10 at 5:31 pm

that last sentence "Eventually, plasma treatments could represent a better option than antibiotics, because microbes will not be able to build up resistance, Ermolaeva said" it was fore mentioned that "Thicker biofilms still show some resistance" whats to stop the bacterium from evolving even thicker biofilms maybe even bioshells?

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St.samples

12/15/10 at 6:16 pm

Unless its 100% effective then wouldn't it leave only bacteria that were resistant. Meaning that future generations from this bacteria would have whatever genetic advantages the original surviving bacteria did. Isn't that how resistance starts or is there something I'm missing?

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Dirk Mcbratney

12/15/10 at 8:18 pm

Actually, no, I don't think so. I'm speculating here, but I think it's a bit like this:

http://i146.photobucket.com/albums/r256/Kalimol/Cells.jpg

Okay, in the upper left of the graphic, we have a colony of two genotypes. Two different antibiotic methods are used, and in each of the results designated by the arrows, something around 50% were destroyed.

In the result at the bottom, all of the individuals of one genotype were wiped out(grey,) but the rest are immune.

In the result at the right, the exposed ones (around the edge) were wiped out, regardless of the genotype, but the ones that weren't exposed survived, again, regardless of genotype.

In other words, a method could be sloppy - in this case, because the plasma couldn't possibly penetrate very deeply into tissue, which it'd have to do in the mouse experiment - and leave survivors through no virtue of their own immunity to the agent used.

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lnwolf41

12/15/10 at 9:21 pm

lnwolf41 If they would go back to copper and brass door fixturs it would greatly reduce the spread of germs. Also this promising in that with a 99% kill rate the body should be able to fight it more effectivly.

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St.samples

12/16/10 at 6:56 pm

Well that makes more sense now. Thanks for the info. You explained it very well.

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Onihikage

12/19/10 at 5:23 am

PopSci needs a +Fav button for articles.

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