新托福阅读材料：青蛙体内的天然抗生素

青蛙，这种看似不起眼的小生物，在地球上已经生活了2亿多年。而它们能健康存活的重要法宝之一就是它们体内含有的一种天然抗生素。近来专家们正积极研究如何提炼这种抗生素为人类健康造福。

 

　　Frogs protect themselves by secreting chemicals that kill germs on their skin. So the theory is that some of these chemicals could be used as antibiotics.

 

　　To find out, researchers in the United Arab Emirates asked colleagues across the world to swab any frogs they found and send them their secretions. They received samples from more than six thousand different species and identified more than a hundred germ-killing chemicals.

 

　　Because they've not been used to combat human diseases before, it's hoped that they might be able to kill bacteria that had become drug-resistant.

 

　　One problem though is that many of these newly-identified chemicals are toxic. So the next step will be to adapt them to make them benign to patients but lethal to bacteria.

 

　　The researchers point out that their work highlights the importance of preserving frog diversity. They say that many species whose skin might contain potentially valuable medicinal substances may become extinct soon because of a loss of habitat and water pollution.

 

　　Notes：

 

　　to secrete something(指动物或植物器官)分泌

 

　　germs细菌

 

　　antibiotics抗生素

 

　　to swab something(医学检验)涂片

 

　　sample采样

 

　　species物种

 

　　to combat something与…斗争

 

　　drug-resistant抗药的，耐药的

 

　　toxic有毒的

 

　　benign有益的，良性的

 

　　bacteria(复数)细菌

 

　　to highlight something强调，突出

 

　　to preserve something保护

 

　　diversity多样性

 

　　extinct灭绝 habitat栖息处