VOA慢速英语 2008 0401a

This is the VOA Special English Agriculture Report.
　

Scientists say flies can spread bacteria in hen houses

The common housefly is unwelcome around food because flies can carry disease-causing germs¹. Now, scientists have shown that the insects can also spread food poisoning bacteria to chickens in poultry² houses. As a result, they say flies are a threat to the safety of poultry products.

Peter Holt and Christopher Geden of the United States Department of Agriculture did a study with Salmonella bacteria. Chickens infected with Salmonella do not get sick, but they can pass the infection to humans through undercooked meat or eggs.

Cases can be mild or severe, or even deadly. The greatest risk is to the old and very young and to people with weak immune³ systems.

The researchers investigated whether infected hens could pass the infection to flies. They also investigated whether those flies could then infect healthy chickens. The research was described last month in the Agriculture Department magazine Agricultural Research.

Peter Holt put uninfected chickens in individual laying cages next to each other in a room. Then Christopher Geden brought in young flies two days away from becoming flying adults. He placed them in an open box in the room with the chickens.

Three days later, the chickens were given Salmonella in their drinking water and became infected. Soon, about half the house flies had Salmonella in and on their bodies. The scientists used a dissecting⁴ microscope to cut the insects apart for study. The number of flies with Salmonella stayed at fifty percent or more for several days.

Next, the researchers placed the newly⁵ infected flies near healthy, uninfected hens. The scientists observed that just being near the infected flies did not infect the hens. But many of the hens did get infected when they ate the flies.

The bacteria grew in the intestines⁶ of close to forty percent of the birds. The crop, a small part in the digestive system that stores predigested food, was mostly free of Salmonella.

Peter Holt says there is much more to learn about the relationship between Salmonella, flies and poultry. But he says the study shows that growers need to be especially careful to control flies.

The findings⁷ show that Salmonella bacteria may not spread around the henhouse by simple physical contact. Instead, eating infected flies seems to be the main way for Salmonella to pass from flies to birds.

And that’s the VOA Special English Agriculture Report, written by Jerilyn Watson. Transcripts⁸ and MP3s of our reports are at voaspecialenglish.com. I'm Steve Ember.

1 germs   

n.微生物( germ的名词复数 )；病菌；起源；发端

参考例句：

• Dirty hands can be a breeding ground for germs. 脏手会滋生病菌。
• The air is full of millions of invisible germs. 空气中充满了许多看不见的细菌。 来自《简明英汉词典》

2 poultry   

n.家禽，禽肉

参考例句：

• There is not much poultry in the shops. 商店里禽肉不太多。
• What do you feed the poultry on? 你们用什么饲料喂养家禽?

3 immune   

adj.免疫的，有免疫力的，不受影响的，免除的

参考例句：

• I am immune from the disease,for I had it once.我对这病有免疫力，因为我已得过一次了。
• Be immune from corruption.拒腐蚀，永不沾。

4 dissecting   

v.解剖（动物等）( dissect的现在分词 )；仔细分析或研究

参考例句：

• Another group was dissecting a new film showing locally. 另外一批人正在剖析城里上演的一部新电影。 来自辞典例句
• Probe into Dissecting Refraction Method Statics Processing under Complicated Surface Conditions. 不同地表条件下土壤侵蚀的坡度效应。 来自互联网

5 newly   

adv.新近，最近；重新，再度；以新的方式

参考例句：

• Have you reviewed for this newly published novel?你给这本新出版的小说写书评了吗？
• It is a newly planted tree and it has not established yet.这是一颗新栽的树，还没有扎下根来。

6 intestines   

n.肠( intestine的名词复数 )

参考例句：

• Perhaps the most serious problems occur in the stomach and intestines. 最严重的问题或许出现在胃和肠里。 来自辞典例句
• The traps of carnivorous plants function a little like the stomachs and small intestines of animals. 食肉植物的捕蝇器起着动物的胃和小肠的作用。 来自辞典例句

7 findings   

n.发现物( finding的名词复数 )；调查（或研究）的结果；（陪审团的）裁决

参考例句：

• It behoves us to study these findings carefully. 我们理应认真研究这些发现。
• Their findings have been widely disseminated . 他们的研究成果已经广为传播。

8 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句