London, 1928: a group of mold spores surf a breeze through a lab. They drift onto a petri dish, and when they land, they germinate a medical revolution. This lab belongs to Alexander Fleming, a Scottish scientist investigating the properties of infectious bacteria. At this time, Fleming is away on vacation. When he returns, he finds a colony of mold growing on a petri dish he’d forgotten to place in his incubator. And around this colony of mold is a zone completely and unexpectedly clear of bacteria.
1928 年,倫敦 一群黴菌孢子隨風飄進一個實驗室 飄落在一個細菌培養皿上 著陸的一刻,萌生一場醫學革命 這個實驗室屬於一位蘇格蘭科學家 亞歷山大·弗萊明 (Alexander Fleming) 他在研究感染性細菌的特性 那時候正遠遊渡假,回來時卻發現 培養皿上孳生一個黴菌菌落 原來這個培養皿忘了放進培養器內 而在黴菌菌落的周圍一帶
In studying this mysterious phenomenon, Fleming came to realize that the mold was secreting some kind of compound that was killing the bacteria. The mold was a species in the Penicillium genus, so Fleming dubbed the antibacterial compound “penicillin.”
出乎意料、乾淨澈底的無菌 弗萊明考究這個神奇現象的背後 發現黴菌釋出一種化合物 足以把細菌殺死 那是青黴屬 (Penicillium genus) 之下其中一種黴菌
What Fleming stumbled upon was a microbial defense system. The penicillium mold constantly produces penicillin in order to defend itself from threats, such as nearby bacterial colonies that might consume its resources. Penicillin destroys many types of bacteria by disrupting synthesis of their cell walls. These walls get their strength from a thick, protective mesh of sugars and amino acids, that are constantly being broken down and rebuilt. Penicillin binds to one of the compounds that weaves this mesh together and prevents the wall from being reconstructed at a critical phase. Meanwhile, penicillin stimulates the release of highly reactive molecules that cause additional damage. Eventually, the cell’s structure breaks down completely. This two-pronged attack is lethal to a wide range of bacteria, whether in petri-dishes, our bodies, or elsewhere. It’s not, however, harmful to our own cells, because those don’t have cell walls.
於是這抗菌化合物就被他命名為 「青黴素」(Penicillin,即盤尼西林) 弗萊明巧遇的是一種微生物防禦機制 青黴屬黴菌會不斷地產生青黴素 以防禦威脅 例如鄰近會耗用資源的細菌菌落 青黴素能破壞許多類型的細菌 全靠阻斷細菌細胞壁的合成 細胞壁的強度來自一層保護厚網 是由糖和胺基酸組成網狀 而且會不斷地分解和重建 青黴素與一種組織成網的化合物結合 在關鍵階段阻止細胞壁重構 青黴素同時刺激高活性分子的釋放 進一步帶來損害 最終,細胞的結構完全瓦解 雙管齊下的攻擊,致多種細菌於死地 不論在培養皿、人體還是他處亦然 對人體細胞則無害 因為人類細胞並沒有細胞壁
For a decade or so after Fleming’s discovery, penicillin remained a laboratory curiosity. But during World War II, researchers figured out how to isolate the active compound and grow the mold in larger quantities. They then went on to win the Nobel Prize for their work. Teams at Oxford and several American drug companies continued development, and within a few years it was commercially available. Penicillin and similar compounds quickly transformed the treatment of infections. For the time being, they remain some of the most important, life-saving antibiotics used in medicine.
繼弗萊明的發現之後,有十年左右 青黴素只是實驗室裡的不尋常之物 直到第二次世界大戰的時候 研究員找到分離活性化合物的方法 大量培養黴菌 他們研究有成,更獲諾貝爾獎表彰 牛津大學及數家美國藥廠繼續研發 數年後,青黴素以商品面世 青黴素之類化合物迅速扭轉感染治療 迄今為止 仍屬醫學中重要的救命抗生素
However, the more we use any antibiotic, the more bacteria evolve resistance to it. In the case of penicillin, some bacteria produce compounds that can break down the key structure that interferes with cell wall synthesis. As antibiotic use has increased, more and more bacteria have evolved this defense, making these antibiotics ineffective against a growing number of bacterial infections. This means it’s essential that doctors not overprescribe the drug.
不過,當一種抗生素用得愈多 細菌愈對那種抗生素演化出抗藥性 以青黴素為例 一些細菌產生出化合物 專門分解阻斷細胞壁合成的關鍵結構 隨著抗生素日益廣泛使用 越來越多細菌演化出這種防禦 讓這些抗生素頓失用武之地 愛莫能助的細菌感染與日俱增 所以醫生萬萬不可過度處方這藥物
Meanwhile, 5 to 15% of patients in developed countries self-identify as allergic to penicillin, making it the most commonly reported drug allergy. However, the vast majority— over 90%— of people who think they’re allergic to penicillin actually are not. Why the misperception? Many patients acquire the allergy label as children, when a rash appears after they’re treated for an infection with penicillin or closely related drugs. The rash is often blamed on penicillin, while the more likely culprit is the original infection, or a reaction between the infection and the antibiotic. However, genuine penicillin allergies, where our immune systems mistake penicillin for an attacker, do occur rarely and can be very dangerous. So if you think you’re allergic but don’t know for sure, your best bet is to visit an allergist. They’ll complete an evaluation that’ll confirm whether or not you have the allergy.
與此同時,已開發國家中的病人 百分之 5 至 15 自訴對青黴素過敏 成為最普遍的呈報藥物過敏 然而當中絕大多數 (即超過九成) 人 自以為對青黴素過敏,其實不然 哪兒來的誤解? 許多病人在兒時被標記為過敏 小時候,有一次治療感染的時候 接受青黴素或密切相關的藥物 之後出現皮疹,就歸咎於青黴素 但實際成因更大可能是原本的感染 或是感染與抗生素之間產生的反應 不過,真正的青黴素過敏也有所聞 人體免疫系統誤認青黴素為攻擊者 雖則罕見,卻可以非常危險 因此若你認為自己有過敏但不肯定 諮詢一下過敏症專家就再好不過了 專家為你完成一個評估後 就會確認你有沒有過敏
Even if you do have a penicillin allergy, your immune cells that react to the drug may lose their ability to recognize it. In fact, about 80% of people who are allergic to penicillin outgrow their allergy within ten years. This is great news for people who currently identify as allergic to penicillin; the drug may one day save their lives, as it has done for so many others.
又即使你對青黴素過敏,隨著年月 產生反應的免疫細胞 或許會失去辨識能力 事實上,約八成青黴素過敏者 十年後不再過敏了 對目前識別為青黴素過敏的人來說 這是個喜訊: 救人無數的藥物