Injecting Yourself with Killer Bacteria

Injecting Yourself with Killer Bacteria


Whether they’re talking about people or
animals, looks can be deceiving. The most innocent-looking critters can pack
a huge punch. Take this tiny fish. Pretty cute, right? Or maybe it’d look like a tasty snack if
you were a predator in a reef. At least, until it reveals a pair of sharp
fangs in its lower jaw, which can inject a potent venom. That’s why it’s called a fangblenny. But there’s a twist to the fangblenny’s
toxic bite. It seriously messes up predators but, unlike
the searing pain from something like a stingray spine, the venom probably doesn’t hurt much
at all. In fact, an international team of biologists
reported this week in the journal Current Biology that one of the chemicals in the venom
is more like a painkiller. So we might even be able to someday use it
in medicine! These were the first scientists to analyze
fangblenny venom. And they found three types of proteins that
act as toxins, none of which had ever been found in fish before. One was a special type of enzyme similar to
those in bee and snake venom, which can do a lot of damage by ripping apart cell membranes. Plus, there was a neuropeptide that’s also
found in cone snails, which could be acting as a neurotransmitter. And the third kind of peptide could bind to
opioid receptors, and block pain, among other effects. Some scorpions use similar proteins. Basically, the itty-bitty fangblenny evolved
a venom that’s snake, snail, and scorpion venom – all rolled into one. As for how this venom works, tests on rats
showed that its main effect is to dramatically lower blood pressure, probably because of
the two peptides. The scientists think this blood pressure drop
could make any predators uncoordinated, or even start violently shaking… even if it’s
not painful because of the opioid-like compound. That’s enough to let a fangblenny slip away
without a scratch. It’s a good enough strategy that lots of
harmless fish have evolved to mimic venomous fangblennies, from their colors to their swimming
styles. And humans might be able to benefit by copying
the fangblenny, too. Scientists who study venoms are always on
the look-out for new molecules that could be useful in medicine, and the researchers
say this unique venom might be worth studying as a new type of painkiller. If it sounds weird to look in fish venom for
new drugs, some scientists are considering an even stranger prospect: using bacteria
as antibiotics. Antibiotics, of course, are supposed to kill
bacteria. So the idea of injecting more bacteria into
your bacteria-ridden body seems… kind of bananas. But this bacterium – called Bdellovibrio
bacteriovorus, or BV for short – could help. In a paper published this week in Biophysical
Journal, scientists learned more about how these assassins hunt. These bacteria might offer a new way to treat
infections that are resistant to multiple drugs, or bust apart biofilms, the slimey
collections of microbes that coat surfaces, like on medical equipment. BV kills other bacteria kind of like a virus
does. It squeezes inside a bacterial cell, replicates,
and then all those clone babies burst out, killing the host. Because it works differently from antibiotics,
which usually target specific bits around or inside bacterial cells, BV can kill bacteria
even after many drugs have failed. Bacteria don’t seem to evolve ways to defend
themselves against this kind of attack. And your cells are safe, because BV can only
grow inside gram-negative bacteria, like E. coli or Salmonella, which have a specific
kind of cell wall surrounding them. But while we know some things about BV’s
life cycle, and even have its genome sequenced, how BV finds its prey has been a mystery. Is BV an active hunter, tracking its victims
by sensing chemical signals? Or is it just bumping into them by chance? Knowing which tactic the bacteria use could
be really helpful in figuring out how to use them as a treatment, whether in hospitals
or human bodies. Well, in the study from this week, scientists
at Indiana University found that BV movement is random, but it has a trick for upping its
chances of running into its victims. The researchers used microscopes to watch
BV, along with some E. coli prey, swimming in some liquid. That swimming is the key. The bacterium has a flagellum that propels
it through water super quickly. It can cover a distance 100 times its body
length in one second! All that tail-whipping makes a lot of swirling
waves, which makes BV swim in circles and zero in on surfaces, or other obstacles – in
this case, microbeads the researchers added. And those surfaces were also the regions with
the most E. coli. E. coli is bigger and slower, but also gets
trapped in the same places because of the way it swims. So, even though BV doesn’t use any chemical
or electrical signals to know what it’s doing, it still ends up where other bacteria
are likely to be. It’s possible scientists could engineer
the bacterium to be even more sensitive and zero in on surfaces faster, which could make
it even an more efficient antibiotic. This episode of SciShow is brought you by
all those patrons on Patreon who give us a little bit of money so that we can make this
free for everybody. If you want to help us out, you can go to
patreon.com/scishow­. And if you just want to help us out by watching,
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99 thoughts on “Injecting Yourself with Killer Bacteria

  1. what if this BV evolves inside a human and becomes harmful or even infectious? Cause nobody can controle that

  2. how do you get the BV back out of your body? How do we prevent it from killing the good gut bacteria for example?
    Pls answer. ๐Ÿ™‚

  3. A bacterium that kills other bacteria by replicating inside them? Isn't that the same idea as engineering bacteriophages to make them target a specific bacterium?

  4. Yo bro I heard you liked parasites so we put a parasite in your parasite so you can parasite while they parasite.

  5. How will they use it as an antibiotic if ur body is going to fight it might have effect the first time cuz the response is slower but the 2ed time it will not work.
    This is without mentioning all the stressful reactions that will happen fighting it!

  6. So, how fundamental is the difference between gram-negative and gram-positive cell walls? Is that a difference BV could by chance evolve to overcome if in sufficient contact with human tissue (because we inject it) ? Or is it too fundamental and the bacterium would have to change its structure?

  7. Hey Hank, thanks for your videos! I've been watching since my first biology class sophmore year of highschool. I'm now a senior in college and never miss one. I'd love more of this same stuff, bacteria and virus videos.๐Ÿ˜Š

  8. You can tell that he knows his audience is science illiterate. And stop throwing your hands around everywhere. You're not conducting.

  9. Guys come on, has any one of you ever been taught well about the human body? No healthy human being has any kind of bacteria in their blood. If E.coli is in there, you're kinda fucked if left untreated, but E.coli is essential to the human body OUTSIDE of the blood stream aka in the guts. They talk about injecting this new bacteria that should combat the ones inside your bloodstream, not outside. Think for a second before you comment.

  10. I have a strange question I thought you might want to take a shot at. If you could breath in space, what would outer space smell like?

  11. what about the e.coli in our guts? that'll make digesting milk or chocolate quite hard without the e.coli in our intestines. BV may help already lactose intolerant people though

  12. BV sounds really cool in the way it works. Also, I'm like "wtf lol" at the fact that those viruses can't adapt their cell walls. I thought viruses could adapt and change, but maybe it's because they've never encounter BV before.

  13. Are these fish and those snakes or bees with similar toxins genetically related in any way? I mean I know we all came from the same ancestors but couldn't we find these toxins by comparing genetics of animals and finding similarities in genes that produce these toxins? Idk much about genetics and toxin production so this may just be impossible Idk. Say we found a matching genetic code in these fish and the snakes and bees with the same toxins, we could test if removing that sequence stops production of that toxin in all 3 species and then we would have a sequence to look for in other species?

    How did we not know what was in the fish's poison or venom whatever it is? Don't we do research on things we find? I mean it would seem to me that whoever is in charge of detailing these species should have sent their stuff off for testing no? I guess that takes time and labor and there are many things to be tested eh? I guess I just assumed we had this stuff on lock, like I thought we were more organized than that. See I never hear anything about what has yet to be discovered or studied. I just assume most everything has been studied already but actually the majority of things have not been studied.

    Some completionists need to get on this databasing and fill out our 100% completion checklist. I mean we don't even have a complete list yet, we have a lot of work to do.

  14. Hey SciShow! I just wanted to say THANK YOU for this video! I'm in my final year doing an infections module at the moment and one of my assignments was to choose ANY microbiology topic, find a recent paper on it, and write a review on the area. I was struggling for what to choose because I wanted something that I found interesting/could write passionately about but would also be kind of unusual and interesting for other people too. Then boom! I watched this video and predatory bacteria is just perfect! What a cool topic. Thank you so much (especially to the script writer who found this area), know that you inspired me! Now I just have to write it… ๐Ÿ™‚

  15. considering that in a typical healthy human being for every 1 cell there are 9 more or less symbiotic bacteria – injecting a bacteria killer does not sound such a thrilling idea…

  16. But we have many species of friendly gram negative bacteria, including some species of E. coli. If the BV kills them , we could become even sicker. I say, careful with that axe, Eugene.

  17. Will B.V. hurt my good bacteria? Once I've been treated with B.V., how do I get it out of my body? So far we only know the health risks of eliminating the good bacteria that inhabit our intestines. We are mostly made of other organisms and remain mostly ignorant as to the consequences of eliminating them. Bacteria mutate, what's to stop B.V. from developing a taste for liver or sweetbreads?

  18. What advantage does having painkiller in venom provide? Wouldn't the pain beneficial for distracting the predator?

  19. Can you make something on Virus, and why Antibiotics are prescribed for cold. And they do work pretty well. Few years back only Amox worked well on cold, now they prescribe a combination drug, but still not very effective.

  20. It'd be horrifying if those bacteria got widespread use and then just one sample of them mutates to infiltrate human cells, creating a flesh eating bacteria that has been engineered and selected for in a way to thrive in the human body.

    Those affected would lose a lot of liquid through all possible means and each drop of it would be full of them. That'd create a terrible pandemic.

  21. Oh look, a fish that could be/could have been driven to extinction without us ever knowing they existed, but that could benefit humanity. Naaa, who cares about all that extinction crap. (sarcastic)

  22. So the fish would give you a pain killer so if it bites a big fish it may not bite back or so if a smaller one is in its mouth it can't get worried and bite the fish?

  23. I'd be worried about the affect BV would have on gut bacteria … Just like antibiotics… Except that in BV's case, it could stick around and permanently alter the human biome in a way that antibiotics wouldn't. — That's my worry anyway… but maybe its unfounded?

  24. The idea of using bacteria to kill bacteria doesn't sound that strange to me at all to be honest, there are actually way more bacteria that produce toxins and other defences against other bacteria than ones that are harmful to us. Of course this makes perfect sense when you think about it logically when you are a microorganism the greatest threat to your continued existence is usually other competing microorganisms not large macroorganisms like animals that operate in very different ecological niches. There are exceptions of course most of the ones I can think of are decomposition microorganisms that compete directly with large scavengers for the same food source.

  25. Wait, wouldn't BV cause damage to the bacteria in our digestive tract which help digest food. If so then couldn't it lead to problems like malnutrition from a lack of the absorption of nutrients.

  26. Oh great! Now there's a fish making painkiller venom… All the junkies are going to work in Wally-World's fish department… as if that wasn't a shopping nightmare already… :o/

  27. Women get Botox injected into their face, which is a variance of Botulinum toxin – Botulinum is the most acutely lethal toxin known. So one little mistake in the production of Botox can have disasterous results.

  28. "humans might be able to benefit from copying the fanged blemmy too"
    That's right girls and boys, paint yo self bright and swim weird

  29. thx for this awesomely ha bisky vid and we cant go after these fishies for painkillers because that will kill all of these kute fishies

  30. my doctor injects me with deactivated Lyme cells to try and prompt my immune system to seek out the dormant Lyme disease cells. We are doing the same with mononucleosis, and hopefully soon west nile since I lucked out and have all three causing Parkinson's like illness. it's called immunotherapy if anyone would be interested in checking it out.

  31. 2:18
    Hank says: "Bdellovibrio bacteriovirus"
    Video says: "Bdellovibrio bacteriovorus"
    Dammit, SciShow, get your shit together ๐Ÿ˜€

  32. great now junkies watching this will start trying to get these fish so they can try and get them to bite them to get high

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