英语听力：VOA双语新闻—大肠杆菌：好菌变坏

　　As a major outbreak of a highly toxic 1 strain of E. coli bacteria continues to sicken residents of Europe, medical experts are racing 2 to find the source.

一种具高度毒性的大肠杆菌造成重大疫情，陆续使欧洲民众染病，现在医学专家正在追踪源头。

E. coli has become a growing public health problem in recent years. The bacteria doesn't usually cause any trouble, says University of Minnesota microbiology professor Michael Sadowski. "E. coli is a normal inhabitant of the intestinal 3 tract 4 of warm-blooded animals."

大肠杆菌在最近几年逐渐形成了公共卫生问题。美国明尼苏达大学的微生物学教授萨道斯基说，大肠杆菌通常不会引起麻烦。他说，“大肠杆菌是温血动物肠道中的正常居民。”

That means you, me, our livestock 5 and even wild animals are all carrying strains of E. coli around in our guts 7. The types that cause disease are rare, Sadowski says.

这意思是，你、我和我们的家畜，甚至野生动物的肠子中都有大肠杆菌。萨道斯基说，大肠杆菌会致病的种类很少。

"The majority of E. coli are in fact considered to be harmless. And they carry out various biochemical processes in your intestine 8 and they help you digest food."

他说，“大多数大肠杆菌实际上都被认为是无害的。而他们在你的肠子里执行多种生化过程，帮助你消化食物。”

And the majority have remained relatively 9 harmless until fairly recently, says University of Minnesota food safety professor Francisco Diez. "We didn't have this type of organism before 1982."

明尼苏达大学食品安全教授迪兹说，直到最近之前，大多数大肠杆菌相对来说都是无害的。

That's when the first deadly strain of E. coli appeared in hamburger meat in the United States. Before then, Diez says, E. coli wasn't even considered a disease-causing germ.

他说，1982年第一起致命的大肠杆菌病例出现在美国的汉堡肉。他说，在那之前，大肠杆菌甚至不被认为是种致病的细菌。

According to Diez, it is not clear exactly how this new virulence 10 developed. It may have been changes in the bacteria, or changes in the way food is produced or distributed. Whatever the cause, E. coli is now turning up in a growing number of fruits and vegetables including apples, lettuce 11, and spinach 12.

迪兹说，还不清楚这种新的毒性是如何发展出来的。有可能是细菌发生了变化，或食物生产或分配方式的变化。不管是哪种原因，大肠杆菌出现在包括苹果、莴苣、菠菜等越来越多的蔬菜水果中。

For a germ that was first found in meat, it seems like a long way to the produce aisle 13. But Diez says there is a connection.

对于一种最初是在肉里发现的细菌，这距离农产品似乎是很遥远的。但迪兹说，这中间是有关联的。

"We've seen an increase in cases of produce-associated outbreaks, but ultimately the source is cattle."

他说，“我们看到越来越多农产品相关的疫情爆发，但最终的源头都是牛。”

He says cattle-manure 14 fertilizer that has not been well composted may still carry live bacteria from the animals’ gut 6. Or manure may contaminate irrigation water. It could also be on the hands of someone picking or sorting the produce. Add storage, transportation, and preparation as other places between the farm and the fork where food can become contaminated with the bacteria.

他说，牛粪肥料如果没被妥善堆肥，就可能还带有动物肠子里活的细菌。或是肥料可能污染了灌溉水。或是肥料可能在一些摘取或挑选农产品的人的手上。还有在农场和手中叉子间食物可能被细菌感染的其他地方，像储藏、运输、预备等。

That's part of why tracing an outbreak to its source is so difficult. In Europe, officials originally blamed Spanish-grown cucumbers, but now they are not so sure. Other suspects include tomatoes and lettuce.

这是很难追踪疫情源头的原因之一。在欧洲，官员最初把矛头指向西班牙的黄瓜，但现在他们不能很确定。其他可疑的还有西红柿和莴苣。

The problem is, those are all common salad ingredients.

美国疾病管制与预防中心的食物病源部门主任布莱登提到，问题是，那些都是很普遍的沙拉成分。

"It's hard to find enough people that only ate one, and only ate one once in the time period before their infection," says Christopher Braden, head of the foodborne disease section at the U.S. Centers for Disease Control and Prevention." They're commonly eaten. They're commonly eaten together. So to try to tease one apart as to which one is the culprit can be difficult."

他说，“很难找到足够的人，他们在感染前只吃其中一种，和只吃一次。我们很常吃这些食物，很常一起吃。所以想把将一种食物和病源食物分开很难。”

Spain maintains that its cucumbers have been falsely accused. Spanish farmers are losing huge amounts of money, and they are furious.

西班牙说，它的黄瓜遭到了不实指控。农民蒙受了巨大的损失，他们非常愤怒。

The CDC was in a similar position in 2008 when it blamed tomatoes for a salmonella outbreak that ultimately was pinned on peppers.

美国疾病管制与预防中心在2008年也遭遇类似的处境。当时它将沙门氏菌疫情归咎于西红柿，但最后矛头指向青椒。

Braden says it can be a hard decision to make when you have preliminary information that points to a suspect. "And in the meantime, people are getting ill and possibly dying in large numbers. Sometimes there's a real balancing act between being fast and being right. Often times it's really hard to do both."

布莱登说，当你有指向可疑食物的初步资料时，这会是个困难的决定。他说，“而同时，人们染上了病，可能有很多人死亡。有时候能在迅速和正确中取得真正的平衡。但通常真的很难两者兼顾。”

He adds that, if their first suspicions proved correct, they could also be criticized if they did not act.

他补充说，就算他们第一个的猜测被证实无误，他们也可能被批评没有作出反应。

There are still a lot of unknowns about the current European outbreak, and it will likely be some time before they are all resolved.

欧洲目前的疫情还有很多未知的地方，在全都明朗化前可能还要一段时间。

In the meantime, the advice remains 15 the same: wash your hands after using the toilet, and before preparing food and eating, and wash counters and utensils 16 that come in contact with raw meat.

在此同时，忠告还是一样的：在如厕后和准备食物和吃饭前洗手。清洗接触生肉的台面和餐具。

And if you are concerned about the cleanliness of raw vegetables, cook them well.

如果担心生菜的清洁，那就煮熟。