The Deadliest Being on Planet Earth – The Bacteriophage — Transcript

Full transcript

1. 0:00[Music]
2. 0:01A war has been raging for billions of years,
3. 0:04killing trillions every single day, while we don't even notice.
4. 0:09The war is fought by the single deadliest entity on our planet:
5. 0:13the bacteriophage
6. 0:15or 'phage' for short.
7. 0:17[Intro + Music]
8. 0:26A phage is a virus;
9. 0:27not quite alive,
10. 0:29not quite dead.
11. 0:30Also, they look as if someone made them up.
12. 0:34Their head is an icosahedron,
13. 0:36a sort of dice with 20 faces and 30 edges.
14. 0:40It contains the genetic material of the virus
15. 0:43and often sits on a long tail that has leg-like fibers.
16. 0:47There are more phages on earth than every other organism combined,
17. 0:51including bacteria.
18. 0:54And they are probably everywhere living things exist.
19. 0:58Billions are on your hands, in your intestines and your eyelids right now.
20. 1:03Which might make you nervous since phages are responsible for the majority of deaths on earth
21. 1:08but you're lucky.
22. 1:11While they do commit genocide for breakfast,
23. 1:13they only kill bacteria.
24. 1:15Up to 40% of all bacteria in the oceans are killed by them every single day.
25. 1:22But phages also have major flaws.
26. 1:24Like any other virus, phages need a host to survive and reproduce.
27. 1:29They're not much more than genetic material in a hull
28. 1:32and they specialize.
29. 1:34Usually, a phage has chosen one specific bacteria
30. 1:37and maybe some of its very close relatives.
31. 1:40These are its prey.
32. 1:43Imagine a phage as like a cruise missile that only hunts and kills members of one very unlucky family.
33. 1:49When a phage finds its victim,
34. 1:51it connects its tail fibers with receptors and uses a sort of syringe to puncture a surface.
35. 1:57In a weird motion, the phage squeezes its tail and injects its genetic information.
36. 2:02Within minutes, the bacteria is taken over.
37. 2:06It's now forced to manufacture all the parts of new phages.
38. 2:10They only stop when the bacteria is filled up with brand-new phages.
39. 2:14In the final step,
40. 2:15they produce 'endolysin',
41. 2:17a powerful enzyme that punches a hole in the bacteria.
42. 2:21The pressure is so high that the bacteria sort of vomits out all of its insides and dies.
43. 2:27New phages are released and begin the cycle anew.
44. 2:32In the last few years,
45. 2:33bacteriophages have enjoyed the attention of the second deadliest beings on earth:
46. 2:38humans.
47. 2:40Recently, we've started looking into injecting millions of them into our bodies
48. 2:44because we're sort of getting desperate;
49. 2:46we screwed up.
50. 2:48In the past a single cut or a sip from the wrong puddle could kill you.
51. 2:53Bacteria were our phages.
52. 2:55Tiny monsters that hunted us mercilessly.
53. 2:58But then, about 100 years ago, we found a solution in nature.
54. 3:02By accident, we found fungi that produced compounds that killed bacteria:
55. 3:07antibiotics.
56. 3:09Suddenly, we had a powerful super weapon.
57. 3:12Antibiotics were so effective that we stopped thinking of bacteria as monsters.
58. 3:17Only the old and the weakest among us were killed by them.
59. 3:21We used antibiotics more and more for less and less serious causes.
60. 3:26We lost respect for the monsters and the weapon
61. 3:30But bacteria are living things that evolve and one by one they started to become immune against our weapons.
62. 3:37This continued until we had created what are called 'superbugs',
63. 3:42bacteria immune to almost everything we have.
64. 3:45This immunity is spreading across the world as we speak.
65. 3:49By 2050, superbugs could kill more humans a year than cancer.
66. 3:54The days when a cut or bladder infection or a cough could kill you or your loved ones are coming back.
67. 4:01In the US alone, more than 23,000 people die from resistant bacteria each year.
68. 4:07But it turns out that phages, our tiny killer virus robots, could save us.
69. 4:13We can inject them into our bodies to help cure infections.
70. 4:17Hold on, how could injecting millions of viruses into an infection be a good idea?
71. 4:24Phages are very very specialized killers of bacteria.
72. 4:28So specialized, in fact, that humans are completely immune to them;
73. 4:32we are too different.
74. 4:34We encounter billions of phages every day and we just politely ignore each other.
75. 4:40Antibiotics are like carpet bombing, killing everything even the good bacteria in our intestines that we don't want to harm
76. 4:48Phages are like guided missiles that only attack what they're supposed to
77. 4:54Wait a minute, if we use phages to kill bacteria, won't bacteria develop ways of defending themselves?
78. 5:00Well, it's more complex than that; phages evolved too.
79. 5:05There has been an arms race between them and bacteria for billions of years and so far, they're doing great.
80. 5:12This makes phages smart weapons that are constantly getting better at killing.
81. 5:19But even if bacteria were to become immune against our phage, we still might be able to win.
82. 5:25It turns out that in order to become resistant to even just a few species of phages,
83. 5:30bacteria have to give up their resistance to antibiotics.
84. 5:34We might be able to trap them in a catch-22.
85. 5:39This has already been successfully tested with a patient who had no other hope left
86. 5:45The bacteria 'Pseudomonas Aeruginosa', one of the most feared bacteria, infected the man's chest cavity.
87. 5:53They are naturally resistant to most antibiotics
88. 5:56and can even survive an alcoholic hand gel.
89. 5:59After years of suffering, a few thousand phages were directly inserted into his chest cavity
90. 6:05together with antibiotics the bacteria were immune to.
91. 6:08After a few weeks, the infections had completely disappeared.
92. 6:13Unfortunately, this treatment is still experimental and pharma companies are still reluctant to invest the necessary billions
93. 6:20in a treatment that has no official approval yet.
94. 6:23But things are finally changing.
95. 6:26In 2016, the largest phage clinical trial to date began and phages are getting more and more attention.
96. 6:34and we better get used to it because the era in which antibiotics have been our super weapon is drawing to a close.
97. 6:42It might be a weird concept but injecting the deadliest being on planet Earth
98. 6:47directly into our bodies could save millions of lives
99. 6:52This video was made possible by a grant from the Bill & Melinda Gates Foundation
100. 6:56If you'd like to support Kurzgesagt, you can do so on patreon.com/Kurzgesagt and get fancy things in return.