Found Inside the Gonorrhea Bacteria: Human DNA

By Andrew Moseman | February 15, 2011 10:18 am

The bacterium called Neisseria gonorrhoeae is what gives humans the sexually transmitted infection gonorrhea. And it also takes something: human DNA. Northwestern University researchers report in the journal mBio that they’ve found pieces of human DNA in samples of the bacteria.

Gonorrhea is one of very few diseases exclusive to our species, and is one of the oldest recorded diseases in human history. An ancient disease that resembles gonorrhea’s symptoms is even described in the Bible, according to Hank Seifert, senior author of a paper on the gene transfer. [Popular Science]

Seifert and colleague Mark Anderson looked at 14 different samples of N. gonorrhoeae. Three of them possessed the chunk of human DNA. And they only saw it in the gonorrhea bacteria:

The pair looked for the same human DNA fragment in the genetically related bacterium Neisseria menigitidis, known to cause meningitis. “We screened many isolates and it wasn’t present,” says Seifert. That means the transfer to N. gonorrhoeae must have occurred since the two bacterial species diverged around 200,000 years ago. [New Scientist]

This is the first such transfer seen from humans to bacteria, though horizontal gene transfer is (somewhat frighteningly) common.

Scientists have observed similar genetic transfers across species, he said — including relatively frequent transfers between different bacteria, between bacteria and viruses or between bacteria and other microbes such as yeast. One particularly significant exchange involves antibiotic resistance genes; when bacteria share these, it can make infections harder to treat with antibiotics. [Los Angeles Times]

But Seifert and Anderson don’t know just how the human DNA chunk got into the gonorrhea bacteria—whether it was a one-time event or not—nor what it might be doing in there. The DNA sequence is missing a key part and not producing a protein, Seifert says, so it’s possibly doing nothing in the virus, and only sticks around because it isn’t harmful, either.

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Image: iStockphoto

CATEGORIZED UNDER: Health & Medicine, Living World
  • Zohar

    This has got to make you wonder if there has ever been any flow the other way, from other species into ours, and that could throw a whole wrench in all of our understanding of genetic history

  • s

    isn’t that how HIV spread from apes to humans?

    anyway – just a thought….if this has human DNA, this might explain why, after 200,000 years, humans have NOT developed an immunity to the disease. On the surface, it seems 200,000 years would be enough time to allow human evolution to fend off this bacteria. but if it contains human DNA, then that probably evolved along with us.

    so…any genetics students out there looking for a thesis idea….there you go.

    lol

  • Zohar

    I don’t know what you’re talking about. There is no Ape DNA in humans or in HIV

  • M Burke

    “An ancient disease that resembles gonorrhea’s symptoms is even described in the Bible”

    If it’s mentioned in the Bible it has to be imaginary! ;)

  • Alyson

    @Zohar there actually is evidence of transfer into human DNA. http://discovermagazine.com/2010/jun/03-the-insanity-virus And absolutely we should be asking some new questions. Like what does it mean to be “human” when so much of our little “world” (our body) is comprised of things “not self.” Even our behaviors can be influenced by the little guests living in our guts and other parts of our bodies. So what makes us “us?” Is the line between us and “them” rather arbitrary?

    It certainly does make you wonder, and opens the door to all sorts of speculation.

  • Alyson

    @M.Burke

    Science types dont look at the Bible the way they should, they are too busy being dismissive.

    You can tell from the ten commandments and other rules in the Bible that STD’s were a pretty big problem in the region at the time. Hence all the “kill the women and men and only keep the virgins to sleep with” and the strict rules against adultery, and circumcision, and all sorts of stuff. Its very clear that some wise person at some point in time had to figure out that the diseases weakening his people were being transferred via sexual activity.

    The ten commandments are a classic guide to “how to live as a group so that you can slaughter other groups more effectively.” In short, the Bible itself is proof of natural selection, if anyone cared to stop being so emotional about it and choose to look at it more objectively.

  • http://www.dnasoa.com John

    This is probably obvious to some, but once human DNA regularly starts passing to bacteria and viruses, get ready. Diseases will start to mutate and and be even harder to fight off. You think these so called “super bugs” are bad. You ain’t seen nothing yet. Keep the money flowing so that we can continue the research to learn more about this and stay at least one step ahead.

  • rabidmob

    Alyson Says: “The ten commandments are a classic guide to “how to live as a group so that you can slaughter other groups more effectively.””

    Since I will take the bait. The 10 commandments strictly prohibit slaughter, murder, or killing.

    @John: It’s likely this has been ongoing long before we even became a species and as such is not a cause for alarm of it’s own.

  • http://www.rationalskepticism.org trubble

    @ rabidmob

    You have to be kidding, right? Have you even read the bible? It chock full of slaughter, murder and killing, much of it as directed by their god. The commandments apply to ‘other people’

  • Wesley

    There’s a potential mechanism here for gene transfer between higher order species, like between mammals. Although it seems unlikely, or at least that it would be rare, but it could be more common than we think!

    As for the Bible, duuuh!! STD’s have been around in humans since before we were human! The bible was written a mere 2 to 3 thousand years ago, it would be strange it if it wasn’t mentioned..

  • http://www.nature.com Biology isn’t Magic

    Can the editor step in and start explaining basic biology to these commenters?

    “This has got to make you wonder if there has ever been any flow the other way, from other species into ours, and that could throw a whole wrench in all of our understanding of genetic history”

    “isn’t that how HIV spread from apes to humans?
    anyway – just a thought….if this has human DNA, this might explain why, after 200,000 years, humans have NOT developed an immunity to the disease. On the surface, it seems 200,000 years would be enough time to allow human evolution to fend off this bacteria. but if it contains human DNA, then that probably evolved along with us.”

    “There is no Ape DNA in humans”

    “This is probably obvious to some, but once human DNA regularly starts passing to bacteria and viruses, get ready. Diseases will start to mutate and and be even harder to fight off. You think these so called “super bugs” are bad. You ain’t seen nothing yet.”

    “There’s a potential mechanism here for gene transfer between higher order species, like between mammals. Although it seems unlikely, or at least that it would be rare, but it could be more common than we think!”

  • Daniel J. Andrews

    I’ll echo comment 11. However, I did find a couple of the comments rather intriguing and behind the misunderstanding I think there is an interesting point or two.

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