地球上最致命的生物——噬菌体：英语精读讲义

A war has been raging for billions of years, 語法

一场战争已经肆虐了数十亿年，

killing trillions every single day while we don't even notice.

每天有数万亿生命被抹杀，而我们甚至毫不知情。

The war is fought by the single deadliest entity on our planet,

这场战争的主角是我们星球上最致命的存在——

the bacteriophage or phage for short. 短語搭配

噬菌体，简称噬菌。

A phage is a virus,

噬菌体是一种病毒，

not quite alive, not quite dead. 表達脈絡

介于生与死之间。

Also, they look as if someone made them up. 講解

而且，它们看起来就像是被凭空捏造出来的一样。

Their head is an icosahedron,

它们的头部是一个二十面体，

a sort of dice with 20 faces and 30 edges. 短語搭配

就像一种有20个面和30条边的骰子。

It contains the genetic material of the virus

里面装有病毒的遗传物质，

and often sits on a long tail that has leg-like fibers.

通常坐落在一个长长的尾巴上，尾巴上还有像腿一样的纤维。

There are more phages on Earth than every other organism combined, 語法

地球上的噬菌体数量比其他所有生物加起来还要多，

including bacteria.

包括细菌。

And they are probably everywhere living things exist.

它们可能存在于所有有生命的地方。

Billions are on your hands,

你的手上有数十亿，

in your intestines,

肠道里有，

and your eyelids right now.

甚至现在的眼皮上也有。

Which might make you nervous

这也许会让你感到紧张，

since phages are responsible for the majority of deaths on Earth.

因为地球上大多数的死亡都是噬菌体造成的。

But you're lucky.

但你很幸运。

While they do commit genocide for breakfast, 習語

虽然它们把种族灭绝当成家常便饭，

they only kill bacteria.

但它们只杀细菌。

Up to 40% of all bacteria in the oceans 短語搭配

海洋中多达40%的细菌

are killed by them every single day.

每天都会被它们杀死。

But phages also have major flaws.

但噬菌体也有很大的缺陷。

Like any other virus,

像其他任何病毒一样，

phages need a host to survive and reproduce. 用詞

噬菌体需要宿主才能生存和繁殖。

They're not much more than genetic material in a hull, 短語搭配

它们不过是装在壳里的遗传物质，

and they specialize.

并且非常专一。

Usually, a phage has chosen one specific bacteria

通常，噬菌体会选择一种特定的细菌，

or maybe some of its very close relatives.

或者一些与之非常亲近的近亲。

These are its prey.

这些就是它的猎物。

Imagine a phage as like a cruise missile

把噬菌体想象成一枚巡航导弹，

that only hunts and kills members of one very unlucky family.

只追捕并猎杀一个非常倒霉的家族成员。

When a phage finds its victim,

当噬菌体找到受害者时，

it connects its tail fibers with receptors

它会将尾部纤维与受体连接起来，

and uses a sort of syringe to puncture the surface.

并用类似注射器的东西刺穿表面。

In a weird motion,

通过一个奇怪的动作，

the phage squeezes its tail and injects its genetic information.

噬菌体挤压尾巴并注入其遗传信息。

Within minutes,

几分钟之内，

the bacteria is taken over. 短語動詞

细菌就被接管了。

It's now forced to manufacture all the parts of new phages. 語法

它现在被迫制造新噬菌体的所有部件。

They only stop when the bacteria is filled up with brand new phages.

直到细菌内部充满了全新的噬菌体，它们才会停止。

In the final step,

在最后一步，

they produce endolysin,

它们会产生内溶素，

a powerful enzyme that punches a hole in the bacteria.

这是一种在细菌上打孔的强大酶。

The pressure is so high 語法

压力如此之大，

that the bacteria sort of vomits out all of its insides and dies.

以至于细菌像是吐出了所有内脏然后死去。

New phages are released and begin the cycle anew.

新的噬菌体被释放出来，重新开始循环。

In the last few years,

在过去的几年里，

bacteriophages have enjoyed the attention of the second deadliest beings on Earth, 短語搭配

噬菌体引起了地球上第二致命生物的注意——

humans.

也就是人类。

Recently,

最近，

we've started looking into injecting millions of them into our bodies 短語動詞

我们开始研究将数以百万计的噬菌体注射到我们体内，

because we're sort of getting desperate. 語氣意圖

因为我们已经有些走投无路了。

We screwed up. 短語動詞

我们搞砸了。

In the past,

在过去，

a single cut or a sip from the wrong puddle could kill you.

一个小伤口或喝错一口泥潭水都能要了你的命。

Bacteria were our phages,

细菌曾是我们的噬菌体，

tiny monsters that hunted us mercilessly.

那些无情猎杀我们的微小怪物。

But then,

但是后来，

about 100 years ago,

大约在100年前，

we found a solution in nature.

我们在自然界找到了解决方案。

By accident, 短語搭配

偶然间，

we found fungi that produced a compound that killed bacteria,

我们发现了能产生杀死细菌的化合物的真菌，

antibiotics.

那就是抗生素。

Suddenly,

突然之间，

we had a powerful super weapon.

我们拥有了强大的超级武器。

Antibiotics were so effective

抗生素非常有效，

that we stopped thinking of bacteria as monsters.

以至于我们不再把细菌当成怪物。

Only the old and the weakest among us were killed by them.

只有我们当中年老和最虚弱的人才会被它们杀死。

We used antibiotics more and more 語法

我们越来越多地使用抗生素，

for less and less serious causes.

用在越来越不严重的病症上。

We lost respect for the monsters

我们失去了对怪物的敬畏，

and the weapon.

也失去了对武器的敬畏。

But bacteria are living things that evolve,

但细菌是会进化的生物，

and one by one,

它们一个接一个地，

they started to become immune against our weapons. 用詞

开始对我们的武器免疫。

This continued

这种情况一直持续，

until we had created what are called superbugs. 語法

直到我们制造出了所谓的“超级细菌”。

Bacteria immune to almost everything we have.

这些细菌对我们几乎所有的武器都免疫。

This immunity is spreading across the world as we speak. 習語

就在我们说话的时候，这种免疫力正在全世界蔓延。

By 2050,

到2050年，

superbugs could kill more humans a year than cancer.

超级细菌每年杀死的人数可能比癌症还要多。

The days when a cut or bladder infection

伤口、膀胱感染

or a cough could kill you or your loved ones

或咳嗽就能夺走你或你所爱之人生命的岁月

are coming back.

正在卷土重来。

In the US alone,

仅在美国，

more than 23,000 people die from resistant bacteria each year.

每年就有超过23,000人死于耐药细菌。

But it turns out that phages, 短語搭配

但事实证明，噬菌体，

our tiny killer virus robots,

这些我们微小的杀手病毒机器人，

could save us.

可能会拯救我们。

We could inject them into our bodies to help cure infections.

我们可以将它们注射到体内来帮助治愈感染。

Hold on. 語氣意圖

等一下。

How can injecting millions of viruses into an infection 語氣意圖

把数以百万计的病毒注射到感染部位，

be a good idea?

怎么会是个好主意呢？

Phages are very,

噬菌体是非常、

very specialized killers of bacteria.

非常专业的细菌杀手。

So specialized,

如此专业，

in fact,

事实上，

that humans are completely immune to them.

以至于人类对它们完全免疫。

We are too different. 語法

我们的差异太大了。

We encounter billions of phages every day

我们每天都会遇到数十亿噬菌体，

and we just politely ignore each other. 習語

而我们只是礼貌地互相无视。

Antibiotics are like carpet bombing, 表達脈絡

抗生素就像地毯式轰炸，

killing everything,

杀光一切，

even the good bacteria in our intestines

甚至是我们肠道里的有益细菌，

that we don't want to harm.

那些我们不想伤害的细菌。

Phages are like guided missiles

而噬菌体就像制导导弹，

that only attack what they're supposed to. 語法

只攻击它们应该攻击的目标。

Wait a minute.

等一下。

If we use phages to kill bacteria,

如果我们用噬菌体杀死细菌，

won't bacteria develop ways of defending themselves?

难道细菌就不会进化出防御的方法吗？

Well,

嗯，

it's more complex than that. 短語搭配

事情远比这复杂。

Phages evolve too.

噬菌体也会进化。

There has been an arms race between them and bacteria 習語

它们与细菌之间的军备竞赛

for billions of years,

已经持续了数十亿年，

and so far,

到目前为止，

they're doing great.

它们做得很好。

This makes phages smart weapons

这让噬菌体成为了智能武器，

that are constantly getting better at killing. 短語搭配

能够不断提升杀戮技巧。

But even if bacteria were to become immune against our phage, 語法

但即使细菌真的对我们的噬菌体免疫了，

we still might be able to win.

我们依然可能获胜。

It turns out that in order to become resistant

事实证明，为了产生抗药性，

to even just a few species of phages,

即便是对少数几种噬菌体产生抗药性，

bacteria have to give up their resistance to antibiotics. 短語動詞

细菌也不得不放弃对抗生素的抗药性。

We might be able to trap them in a catch-22. 習語

我们也许能将它们困在两难的境地。

This has already been successfully tested with a patient

这已经在一个患者身上得到了成功测试，

who had no other hope left.

他本来已经没有其他希望了。

The bacteria Pseudomonas aeruginosa, 文化背景

绿脓杆菌，

one of the most feared bacteria,

最令人恐惧的细菌之一，

infected the man's chest cavity.

感染了这名男子的胸腔。

They are naturally resistant to most antibiotics 用詞

它们天生对大多数抗生素具有抗药性，

and can even survive in alcoholic hand gel.

甚至能在含酒精的洗手液中存活。

After years of suffering,

在遭受了多年的痛苦之后，

a few thousand phages were directly inserted into his chest cavity,

几千个噬菌体被直接注入了他的胸腔，

together with antibiotics the bacteria were immune to.

连同细菌免疫的抗生素一起。

After a few weeks,

几周后，

the infections had completely disappeared. 語法

感染彻底消失了。

Unfortunately,

不幸的是，

this treatment is still experimental

这种疗法仍处于实验阶段，

and pharma companies are still reluctant to invest the necessary billions 短語搭配

制药公司仍然不愿投入所需的数十亿美元，

in a treatment that has no official approval yet. 用詞

去开发这种尚未获得官方批准的疗法。

But things are finally changing.

但情况终于在发生变化。

In 2016,

2016年，

the largest phage clinical trial to date began, 短語搭配

迄今为止最大规模的噬菌体临床试验开始了，

and phages are getting more and more attention.

噬菌体正受到越来越多的关注。

And we better get used to it 語法

我们最好习惯这一点，

because the era in which antibiotics have been our super weapon

因为抗生素作为我们超级武器的时代

is drawing to a close. 習語

正在接近尾声。

It might be a weird concept,

这个概念可能听起来很怪异，

but injecting the deadliest being on planet Earth

但将地球上最致命的生物

directly into our bodies

直接注射到我们体内，

could save millions of lives.

可能会拯救数百万人的生命。

This video was made possible

本视频得以制作，

by a grant from the Bill and Melinda Gates Foundation.

要感谢比尔及梅琳达·盖茨基金会的资助。

If you'd like to support Kurzgesagt,

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you can do so on patreon.com/kurzgesagt

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