科學家發現 細菌可以對抗新型抗生素

Perhaps the chief poster child of antibiotic resistance is methicillin-resistant Staphylococcus aureus, or MRSA. The bacterium is impervious to a suite of antibiotics, and can cause blood infections, pneumonia…even death.

也許抗生素耐藥性的主要代表就是耐甲氧西林金黃色葡萄球菌（MRSA）這種細菌，它不受系列抗生素的影響，還能引起感染、肺炎甚至死亡。

And you'd assume that it developed its namesake resistance to methicillin…by being exposed to methicillin.

你會認爲它之所以有耐藥性，是因爲它暴露於甲氧西林中。

But that doesn't seem to be the case. Instead, the culprit for resistance appears to be an earlier, and chemically related antibiotic: penicillin.

但並不是這樣的。相反，耐藥性的罪魁禍首似乎是早期的，與化學相關的抗生素：盤尼西林。

"We think it's a very early use of penicillin that forced the strains to pick up these mechanisms." Matthew Holden, a molecular microbiologist at the University of Saint Andrews in Scotland.

蘇格蘭聖安德魯斯大學的分子微生物學家馬修·霍爾登表示：“我們認爲是早期使用青黴素，使菌株提取了這些機制。”

Holden and his team analyzed the genomes of freeze-dried strains of MRSA bacteria, from the 1960s through the '80s.

霍爾登和他的團隊分析了20世紀60年代至80年代經過冷凍乾燥處理的MRSA細菌基因組。

"In effect what we were doing was sort of genomic archaeology, in looking at the genomes, and comparing the variation and using that information to effectively reconstruct the evolutionary histories," he said.

他說：“實際上，我們有點像做基因組考古研究。通過比較分析，得出變異基因組並利用這些信息進行有效地重新構建細菌進化史。”

What they found was that the Staph bacteria seem to have acquired the methicillin-resistance gene in the mid-1940s—about 15 years before methicillin even hit the market.

他們發現，葡萄球菌似乎於20世紀40年代中期就有了耐藥性的基因--大約在甲氧西林進入市場15年前時候。

And they determined that it was the widespread use of penicillin that led to that adaptation. The results are in the journal Genome Biology.

他們得出結論，正是青黴素的廣泛使用纔出現了耐藥性適應性。這項研究結果發表在《基因生物學》雜誌上。

Methicillin was introduced in the U.K. in 1959. Less than a year later, resistance was first reported—resistance that it appears now was already baked into the staph strains.

甲氧西林由英國於1959年引入。不到一年時間，就出現了第一次抗藥性的報道--一種似乎現在已經進入了葡萄球菌菌株的耐藥性。

Looking ahead, Holden says we'd do well to vigilantly monitor the genetics of circulating strains—to find out which bugs may be armed to battle our newest antibiotics as soon as they're developed.

霍爾登稱，我們要非常謹慎地監控細菌菌株的基因遺傳，這樣才能查明，在抗生素開發出來之前，有哪些細菌可能會出現抗藥性。