Logo
Home
language
سياسة الخصوصية·شروط الخدمة

تدريب الاستماع

تدريب الاستماع/Video/MinuteEarth/Where have all the antibiotics gone?

Where have all the antibiotics gone?

اختر وضع التعلم:

Highlight:

3000 Oxford Words4000 IELTS Words5000 Oxford Words3000 Common Words1000 TOEIC Words5000 TOEFL Words

ترجمة (16)

0:00Almost all our antibiotics have been discovered  in the exact same way: scientists take a sample  
0:05of soil – which tends to contain tons of  microbes – and grow those microbes on a  
0:09petri dish to see if they produce any chemical  weapons that could possibly be useful to us. 
0:15Early on, this approach kept turning up  new types of antibiotics: some that attack  
0:20bacteria’s cell walls, others that attack  their protein production, still others  
0:24that attack their DNA. But in the 1970s, these  discoveries stopped; instead, researchers just  
0:31kept finding new variations of the same old  types of antibiotics they already knew about. 
0:37Now, the problem had to do with the basic  discovery process. Only about 3% of known  
0:43microbes actually reproduce in petri dishes. Because of this discovery drought, doctors haven’t  
0:49been able to prescribe a new type of antibiotic  in nearly 40 years. And in the meantime, bacteria  
0:54have been evolving resistance to the antibiotics  we DO have, leaving some of these weapons –that  
0:59were once great– powerless. So scientists are switching  
1:03up their search strategies. And these days, researchers don’t  
1:06even have to grow microbes to see what they’re  capable of; they can simply sift through their  
1:10DNA to identify potential antibiotic-making genes.  Scientists are also looking for microbes in places  
1:17other than soil, like the ocean, which is full of  unknown – and potentially useful – microbial life.