by Megan Hamilton
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March 22, 2012 How Sneaky Lyme Disease Bacteria Use Manganese to Fool the Immune System
March 24, 2013 01:25 AM EDT
humans, must eat in order to survive. Also, like humans, they utilize iron and other metals to produce the protein and enzymes that are essential for their survival. Normally, when humans get sick due to these misbehaving bugs, the iron produced by these little naughty no-nos is detected by the immune system, which then swings into action, according to LiveScience.
What does the immune system do?
It puts these troublesome microbes on a very strict diet, meaning no iron whatsoever, starving them out of existence. The immune system does this by inducing the liver to produce a hormone that inhibits iron from being absorbed by the gut and by the bloodstream, according to this article in Science Daily.
However, one species of these nefarious bugs has managed to hoodwink the immune system. In fact, these particular troublemakers don't even have the genes that help to produce the proteins which accumulate iron, according to the article. As the only known organism that exists without utilizing iron, Borrelia burgdorferi, the bacterium that causes Lyme disease instead produces massive amounts of manganese, especially in the areas where it needs to defend itself against the immune system. It uses all that manganese in order to cause Lyme Disease.
Pretty wily for itty-bitty prokaryotic organisms that don't even have brains.
Undoubtedly, most people know by now that Lyme Disease starts with a tick bite.
It has some rather unlovely symptoms, according to LiveScience, including: fever, fatigue, headaches, and rashes. If it isn't treated with the appropriate antibiotics, Lyme Disease can also cause problems for the central nervous system and the cardiovascular system. It's quite amazing that something which can't even be seen with the naked eye can cause so much trouble.
The immune system, like a blood hound with a stuffed up sniffer, doesn't detect the manganese. So from then on, it's party on for Borrelia but a not-so-good time for those now infected with Lyme Disease, a disease that is frequently slow growing and difficult to detect, the article in Science Daily mentions.
Scientists are optimistic that the manganese discovery will open up new options in the treatment of Lyme Disease, said Dr. Valeria Culotta, who is a molecular biologist at the Johns Hopkins University Bloomberg School of Public Health.
"The only therapy for Lyme Disease right now are antibiotics like penicillin, which are effective if the disease is detected early enough," Culotta said in a statement, according to LiveScience. Penicillin attacks Borrelia's cell walls, but the problem is, not all of these critters have cell walls.
Using sophisticated equipment, Culotta and her fellow scientists were able to measure proteins that contained metals all the way down to parts per trillion, LiveScience reported.
"We'd like to find targets inside pathogenic (disease-causing) cells that could thwart their growth," Culotta said.
The next step will be mapping out all the proteins containing metal that inhabit Borrelia. Then the researchers will try to learn how the microbe sucks the manganese in from its surrounding environment, LiveScience reported. The manganese might be the weak link in the bacteria's chain mail, and the researchers can exploit this.
What's the best way to do that?
"The best targets are enzymes that pathogens have, but people do not, so they would kill the pathogens but not harm people," Culotta said, according to LiveScience.
By working for the common good, these scientists may have found a way to beat this nefarious critter at its own game. This is science at it's best.
Lyme Disease distribution map courtesy of Wikimedia Commons.
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