白色念珠菌会掌握时机向人体发起进攻

时间：2012-07-25 05:55:25

（单词翻译:单击）

The opportunistic fungal pathogen Candida albicans（白色念珠菌） inconspicuously（难以觉察地） lives in our bodies until it senses that we are weak, when it quickly adapts to go on the offensive. The fungus1, known for causing yeast2 and other minor3 infections, also causes a sometimes-fatal infection known as candidemia（念珠菌血症） in immunocompromised patients. An in vivo study, published in mBio, demonstrates how C. albicans can distinguish between a healthy and an unhealthy host and alter its physiology4（生理机能） to attack. "The ability of the fungus to sense the immune status of its host may be key to its ability to colonize5 harmlessly in some people but become a deadly pathogen in others," said Jessica V. Pierce, BA, PhD student in the molecular6 microbiology program at the Sackler School of Graduate Biomedical Sciences at Tufts.

 
"Effective detection and treatment of disease in immunocompromised patients could potentially work by targeting the levels of a protein, Efg1p, that we found influenced the growth of Candida albicans inside the host," she continued.
 
The researchers knew from previous research that Efg1p influences the expression of genes7 that regulate how harmful a fungal cell can become. Surprisingly, the investigators8 found that lower Efg1p levels allow the fungal cells to grow to high levels inside a host. Higher levels of the protein result in less growth.
 
To examine how the immune status could affect the growth of C. albicans within a host, the researchers fed both healthy and immunocompromised mice equal amounts of two fungal strains containing two different levels of the Efg1p protein.
 
Fecal pellets from the mice were tested to determine which strain of fungi9 thrived. In a healthy host, the fungal cells with higher levels of the protein predominated.
 
In immunocompromised mice, the fungal cells with lower levels of the protein flourished. The researchers noted10 that lack of interactions with immune cells in the intestinal11 tract12 most likely caused the necessary environmental conditions favoring fungal cells that express lower levels of the protein, resulting in fungal overgrowth and setting the stage for systemic infection.
 
"By having a mixed population with some high Efg1p cells and some low Efg1p cells, the fungus can adjust its physiology to remain benign13 or become harmful when it colonizes14 hosts with varying immune statuses. These findings are important because they provide the first steps toward developing more effective methods for detecting and treating serious and stubborn infections caused by Candida albicans, such as candidemia," said Carol A. Kumamoto, PhD, professor of molecular biology and microbiology at Tufts University School of Medicine and member of the molecular microbiology and genetics program faculties15 at the Sackler School of Graduate Biomedical Sciences.

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1 fungus gzRyI     
n.真菌，真菌类植物
参考例句：
  • Mushrooms are a type of fungus.蘑菇是一种真菌。
  • This fungus can just be detected by the unaided eye.这种真菌只用肉眼就能检查出。
2 yeast 7VIzu     
n.酵母；酵母片；泡沫；v.发酵；起泡沫
参考例句：
  • Yeast can be used in making beer and bread.酵母可用于酿啤酒和发面包。
  • The yeast began to work.酵母开始发酵。
3 minor e7fzR     
adj.较小(少)的，较次要的；n.辅修学科；vi.辅修
参考例句：
  • The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
  • I gave him a minor share of my wealth.我把小部分财产给了他。
4 physiology uAfyL     
n.生理学，生理机能
参考例句：
  • He bought a book about physiology.他买了一本生理学方面的书。
  • He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。
5 colonize mqzzM     
v.建立殖民地，拓殖；定居，居于
参考例句：
  • Around 700 Arabs began to colonize East Africa.公元700年阿拉伯人开始把东非变为殖民地。
  • Japan used to colonize many countries in Asia.日本曾经殖民过许多亚洲国家。
6 molecular mE9xh     
adj.分子的；克分子的
参考例句：
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。
7 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
参考例句：
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
8 investigators e970f9140785518a87fc81641b7c89f7     
n.调查者，审查者( investigator的名词复数 )
参考例句：
  • This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
  • The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》
9 fungi 6hRx6     
n.真菌，霉菌
参考例句：
  • Students practice to apply the study of genetics to multicellular plants and fungi.学生们练习把基因学应用到多细胞植物和真菌中。
  • The lawn was covered with fungi.草地上到处都是蘑菇。
10 noted 5n4zXc     
adj.著名的，知名的
参考例句：
  • The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
  • Jim is noted for arriving late for work.吉姆上班迟到出了名。
11 intestinal DbHzX     
adj.肠的；肠壁；肠道细菌
参考例句：
  • A few other conditions are in high intestinal obstruction. 其它少数情况是高位肠梗阻。 来自辞典例句
  • This complication has occasionally occurred following the use of intestinal antiseptics. 这种并发症偶而发生在使用肠道抗菌剂上。 来自辞典例句
12 tract iJxz4     
n.传单，小册子，大片(土地或森林)
参考例句：
  • He owns a large tract of forest.他拥有一大片森林。
  • He wrote a tract on this subject.他曾对此写了一篇短文。
13 benign 2t2zw     
adj.善良的，慈祥的；良性的，无危险的
参考例句：
  • The benign weather brought North America a bumper crop.温和的气候给北美带来大丰收。
  • Martha is a benign old lady.玛莎是个仁慈的老妇人。
14 colonizes 947213942bc90046fcbb2e6dfb26eaf8     
开拓殖民地，移民于殖民地( colonize的名词复数 )
参考例句：
15 faculties 066198190456ba4e2b0a2bda2034dfc5     
n.能力( faculty的名词复数 )；全体教职员；技巧；院
参考例句：
  • Although he's ninety, his mental faculties remain unimpaired. 他虽年届九旬，但头脑仍然清晰。
  • All your faculties have come into play in your work. 在你的工作中，你的全部才能已起到了作用。 来自《简明英汉词典》

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