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刺猬耐藥簡史 刺猬擁有多重特點(diǎn)：它們小巧卻尖銳，渾身是刺卻在一些人看來甚是可愛?，F(xiàn)在，一項(xiàng)新研究表示，刺猬還是一種提取自青霉素的抗生素——甲氧西林耐藥性的源頭。這一尖銳觀點(diǎn)發(fā)表在《自然》（Nature）期刊上。 抗生素耐藥性是一個嚴(yán)重的臨床問題。耐甲氧西林的金黃色葡萄球菌（Staphylococcus aureus），也就是MRSA的感染難以治療，因?yàn)樵S多人已經(jīng)對屈指可數(shù)的一線治療藥物產(chǎn)生了耐藥性。 “過去我們認(rèn)為，包括金黃色葡萄球菌在內(nèi)的致病菌耐藥性是一種現(xiàn)代才出現(xiàn)的現(xiàn)象，由臨床使用抗生素所致?！?丹麥國家血清研究所（Statens Serum Institute）的資深科學(xué)家杰斯珀·拉森（Jesper Larsen）說道。該研究所在丹麥的地位相當(dāng)于美國疾病控制和預(yù)防中心（CDC）在美國的地位。 甲氧西林耐藥性被認(rèn)為與處方藥相關(guān)，一部分原因是在該藥物獲得臨床使用后的一年內(nèi)，英國醫(yī)院就率先分離了出甲氧西林耐藥菌。 拉森繼續(xù)說：“但幾年前，我們偶然發(fā)現(xiàn)在丹麥和瑞典，60%以上的刺猬體內(nèi)存在mecC M-R-S-A?！?/span> 什么是mecC M-R-S-A？甲氧西林和青霉素屬于β-內(nèi)酰胺類抗生素，細(xì)菌通過酶來構(gòu)建自己的保護(hù)性細(xì)胞壁，而β-內(nèi)酰胺類抗生素則通過抑制這些酶來殺死細(xì)菌。但mecC以及相關(guān)基因mecA能編碼抗生素也無法破壞的酶。 “因此，攜帶這些基因的金黃色葡萄球菌對大部分β-內(nèi)酰胺類抗生素都具有耐藥性?！?/span> 但是，這些耐藥性基因又從哪里來呢？它們不僅出現(xiàn)在感染了金黃色葡萄球菌的人體內(nèi)，還出現(xiàn)在家畜，例如豬和牛，甚至一些野生動物體內(nèi)。在瑞典，拉森發(fā)現(xiàn)mecC常見于刺猬體內(nèi)。 “所以大問題來了……[查看全文] Hedgehogs Host the Evolution of Antibiotic Resistance Karen Hopkin: Hedgehogs are a lot of things. They’re small and spiky, covered in quills. And some people even say they’re cute. Now, a new study says that they are also the origin of resistance to methicillin, an antibiotic derived from penicillin. That pointed observation appears in the journal Nature. Antibiotic resistance is a huge clinical problem. And methicillin-resistant Staphylococcus aureus…otherwise known as M-R-S-A or MRSA…can be difficult to treat as many have developed resistance to a handful of our frontline therapeutics. Jesper Larsen: Historically it has been assumed that resistance in disease-causing bacteria, including Staph aureus, is a modern phenomenon driven by clinical use of antibiotics. Hopkin: Jesper Larsen is a senior scientist at the Statens Serum Institute in Copenhagen… Larsen: …which is the Danish equivalent of the CDC in the US. Hopkin: Methicillin resistance was thought to be tied to prescription, in part because methicillin-resistant bugs were first isolated from British hospitals just a year after the drug became available for clinical use. Larsen: But a couple of years ago we found out by chance that mecC M-R-S-A is present in more than 60 percent of hedgehogs from Denmark and Sweden. Hopkin: Ok, what’s mecC M-R-S-A? Methicillin and penicillin belong to the so-called “beta lactam” family of antibiotics. They kill bacteria by inhibiting enzymes the bugs use to build their protective cell walls. mecC…and a related gene mecA…encode versions of the enzymes that the antibiotics don’t latch onto as well. Larsen: Staph aureus bacteria that carry these genes are therefore resistant to most beta lactam antibiotics. Hopkin: But where did these resistance genes come from? They’ve been spotted not only In folks with Staph infections, but in livestock…like pigs and cattle…and in some wild animals. And in Sweden, Larsen found that mecC is really common in hedgehogs. Larsen: So the big question was...[full transcript] “ Larsen, J., Raisen, C.L., Ba, X. et al. Emergence of methicillin resistance predates the clinical use of antibiotics. Nature 602, 135–141 (2022). 封面圖來源：Unsplash |
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