英语听力文摘 English Digest 210、细菌里的防护栏(在线收听

  Fencing in Bacteria
  绿脓杆菌(p.aeruginosa)或称铜绿色假单胞菌,是一种致病力较低但抗药性强的杆菌。广泛存在于自然界,是伤口感染较常见的一种细菌。能引起化脓性病变。感染后因脓汁和渗出液等病料呈绿色,故名。绿脓杆菌(p.aeruginosa)属假单胞菌属(pseudomonas),广泛分布于自然界及正常人皮肤、肠道和呼吸道,是临床上较常见的条件致病菌之一。
  What do you do when infected with Pseudomonas aeruginosa? You'll want to know! Find out on this Moment of Science.
  You know how they say good fences make good neighbors? Well, this adage might have some applications in medicine. Imagine that you go in for major surgery, and get a post-op infection with Pseudomonas aeruginosa. What do you do?
  Pseudomonas is especially virulent in that it slides right by your immune system, and is resistant to antibiotics. But the thing is that Pseudomonas bacteria live contentedly in the bowels of about three percent of all people, which adds up to almost nine million Americans.

  But when your body undergoes major stress, like surgery, the Pseudomonas bacteria may respond to the changes in your body’s chemistry, and to the erosion of the mucus that coats the intestines that occurs whenever you’re hooked up to an IV and nutrients bypass the digestive system. When that happens, Pseudomonas go on the attack, boring through the intestines’ lining and into the bloodstream. It’s best to avoid agitating the bacteria in the first place.
  Well,in one study, scientists were able to prevent post-op infection in mice by coating their intestines with a high-molecular-weight polymer. This worked as a bio shield to prevent the chemical signs of stress from reaching the bacteria, while also acting as a barrier, like mucus. Mice that normally would have died managed to survive with no noticeable side effects.
  It’s a promising study, and scientists hope to refine it so that one day we’ll be able to fight off infections by preventing them in the first place.

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