The accident that changed the world - Allison Ramsey and Mary Staicu

翻译人员: Isabella Lu 校对人员: 宁玥 沈

London, 1928: a group of mold spores surf a breeze through a lab.

伦敦，1928 年： 一组霉菌孢子被一阵风吹过实验室，

They drift onto a petri dish, and when they land,

它们飘过一个培养皿， 当它们降落之后，

they germinate a medical revolution.

一场医学革命开始生根发芽。

This lab belongs to Alexander Fleming, a Scottish scientist

这个实验室的负责人是 亚历山大·弗莱明（Alexander Fleming），

一位正在研究细菌感染 特性的苏格兰科学家。

investigating the properties of infectious bacteria.

At this time, Fleming is away on vacation.

这时，弗莱明正在度假。

When he returns, he finds a colony of mold growing on a petri dish

回来时，他发现他忘记放在恒温器内的培养皿上

he’d forgotten to place in his incubator.

他忘记放在恒温器内的培养皿上。

And around this colony of mold is a zone

在这个霉菌群周围的一片区域

completely and unexpectedly clear of bacteria.

出乎意料地没有任何细菌。

In studying this mysterious phenomenon,

在研究这一神秘现象时，

Fleming came to realize that the mold was secreting some kind of compound

弗莱明发现霉菌中隐藏着一种

that was killing the bacteria.

能杀死细菌的化合物。

The mold was a species in the Penicillium genus,

这个霉菌是青霉菌属中的一株，

so Fleming dubbed the antibacterial compound “penicillin.”

于是弗莱明将这种 抗菌化合物命名为“青霉素”。

What Fleming stumbled upon was a microbial defense system.

弗莱明偶然发现的其实是 一种微生物防御系统。

The penicillium mold constantly produces penicillin

青霉属真菌不停地产生青霉素

in order to defend itself from threats,

来保护自己免受威胁，

such as nearby bacterial colonies that might consume its resources.

比如周围可能会占用它资源的菌落。

Penicillin destroys many types of bacteria

青霉素通过破坏细菌细胞壁的合成

by disrupting synthesis of their cell walls.

来摧毁多种细菌。

These walls get their strength from a thick, protective mesh of sugars

这些细胞壁的强度来自于一个

由糖和氨基酸组成的厚实、 且有保护性的网状结构，

and amino acids,

that are constantly being broken down and rebuilt.

它们不停地瓦解、再生。

Penicillin binds to one of the compounds that weaves this mesh together

青霉素将自己和其中一种 编织保护网的化合物绑在一起，

and prevents the wall from being reconstructed at a critical phase.

在关键阶段阻止了细胞壁的重建。

Meanwhile, penicillin stimulates the release of highly reactive molecules

同时，青霉素刺激并释放 具有破坏作用的

that cause additional damage.

高度活跃的分子。

Eventually, the cell’s structure breaks down completely.

最终，细胞的结构完全崩塌了。

This two-pronged attack is lethal to a wide range of bacteria,

这种双向攻击 对很多种类的细菌都是致命的，

whether in petri-dishes, our bodies, or elsewhere.

不论是在培养皿中、我们身体里， 还是其他的地方。

It’s not, however, harmful to our own cells,

但它对我们自身的细胞是无害的，

because those don’t have cell walls.

因为人体细胞没有细胞壁。

For a decade or so after Fleming’s discovery,

在弗莱明这一发现诞生的十年后，

penicillin remained a laboratory curiosity.

青霉素仍然只停留在实验室阶段。

But during World War II,

但在二战期间，

researchers figured out how to isolate the active compound

研究人员发现了 如何分离出活性化合物

and grow the mold in larger quantities.

并大量培养这种霉菌。

They then went on to win the Nobel Prize for their work.

这项成就随后让他们获得了诺贝尔奖。

Teams at Oxford and several American drug companies continued development,

牛津和一些美国制药公司的 研究团队继续推进了这个项目，

and within a few years it was commercially available.

几年之内就实现了商业化。

Penicillin and similar compounds quickly transformed the treatment of infections.

青霉素和其他相似的化合物 迅速改变了感染的治疗方式。

For the time being,

直到现在，

they remain some of the most important, life-saving antibiotics used in medicine.

它们仍是医学上最重要的 挽救生命的抗生素之一。

However, the more we use any antibiotic, the more bacteria evolve resistance to it.

但是，我们越多地使用一种抗生素， 细菌就会更容易产生抗药性。

In the case of penicillin,

对于青霉素，

some bacteria produce compounds that can break down the key structure

一些细菌生产出了可以瓦解

抑制细胞壁合成结构的化合物。

that interferes with cell wall synthesis.

随着抗生素的使用频率越来越高，

As antibiotic use has increased,

more and more bacteria have evolved this defense,

越来越多的细菌进化出了 这种保护机制，

making these antibiotics ineffective

使这些抗生素对

越来越多的细菌感染不再有效。

against a growing number of bacterial infections.

This means it’s essential that doctors not overprescribe the drug.

这使得医生不滥用抗生素 处方变得尤为重要。

Meanwhile, 5 to 15% of patients in developed countries

同时，发达国家中有 5-15% 的病患

self-identify as allergic to penicillin,

自认为他们对青霉素过敏，

making it the most commonly reported drug allergy.

使青霉素成为最普遍的药物过敏源。

However, the vast majority— over 90%— of people

但是，大多数，即超过 90%

who think they’re allergic to penicillin actually are not.

自认为对青霉素过敏的人， 但其实并不过敏。

Why the misperception?

这个误解从何而来？

Many patients acquire the allergy label as children,

很多病人在孩童时期 就被认为是过敏者，

when a rash appears after they’re treated for an infection with penicillin

因为他们用青霉素或相关 药物治疗后

出现了皮疹。

or closely related drugs.

The rash is often blamed on penicillin,

皮疹的出现通常被归罪于青霉素，

while the more likely culprit is the original infection,

但其实更大可能是因为原始的感染，

or a reaction between the infection and the antibiotic.

或者感染和抗生素之间的反应。

However, genuine penicillin allergies,

但是，真正的青霉素过敏，

where our immune systems mistake penicillin for an attacker,

也就是当我们的免疫系统 错把青霉素当成入侵者时，

do occur rarely and can be very dangerous.

的确会以很低的概率出现， 并且可能危及生命。

So if you think you’re allergic but don’t know for sure,

所以如果你认为自己 对青霉素过敏，但并不确定，

your best bet is to visit an allergist.

最好的办法是去看过敏症专家。

They’ll complete an evaluation that’ll confirm

他们会做一项评估来证实

whether or not you have the allergy.

你是否对青霉素过敏。

就算你的确对青霉素过敏，

Even if you do have a penicillin allergy,

your immune cells that react to the drug may lose their ability to recognize it.

你对青霉素产生反应的免疫细胞 也有可能已经丧失识别出它们的能力。

In fact, about 80% of people who are allergic to penicillin

实际上，大约 80% 的青霉素过敏者

outgrow their allergy within ten years.

可以在十年内自己摆脱过敏症状。

This is great news for people who currently identify

这对于现在被认为 对青霉素过敏的人来说

as allergic to penicillin;

是很好的消息。

the drug may one day save their lives, as it has done for so many others.

或许某一天，这个挽救了无数人的药物 也会同样挽救他们的生命。