VOA标准英语2010年-Use of Antibiotics in Livestock Debate

Animals in many large livestock¹-raising operations around the world get a small but steady dose of certain antibiotics³ in their feed.

Doctors around the world are finding it harder and harder to cure some infections. Bacteria are developing resistance to the drugs used to kill them. Health experts point to doctors over-prescribing antibiotics, and patients misusing⁴ them, as part of the problem. Many also say the meat industry is contributing by feeding animals antibiotics to help them grow better.

In the late 1980s, doctors in Europe were finding that vancomycin, one of the most potent⁵ antibiotics in the medicine cabinet, was not working as well as it used to. Certain bacteria had developed resistance to it, even though doctors were not using very much of this drug of last resort.

But a drug similar to vancomycin was widely used in livestock at the time.

"They used, hundreds of tons of this drug in animal husbandry in Europe, while we only used kilograms of vancomycin," says Niels Frimodt-Moller, head of antibiotic² research at the Danish State Serum⁶ Institute.

Steady diet of antibiotics

Animals in many large livestock-raising operations around the world get a small but steady dose of certain antibiotics in their feed. It keeps the animals healthy, and that promotes their growth.

But when bacteria are steadily⁷ exposed to an antibiotic, they will eventually develop resistance. Frimodt-Moller said a number of studies linked vancomycin-resistant⁸ bacteria in people to use of the animal drug as a growth promoter.

"It could be shown that [the bacteria were] transmitted by food to humans in hospitals, and in non-hospitalized humans, and we found the same types in infections," Frimodt-Moller says, "So there was good reason for banning the growth promoters."

Banned in Denmark

Denmark banned the drug's use as a growth promoter in 1996, and levels of resistant bacteria found in animals and meat declined. The European Union has since banned the use of several other antibiotics as growth promoters.

But there is disagreement over how effective Denmark's ban has been.

Over-use in animal husbandry is not the only source of antibiotic resistance. Health experts point to doctors over-prescribing antibiotics, and patients misusing them, as another part of the problem.

And the growth-promoter ban does not appear to have made much difference in the overall rates of resistant infections in people, says Rich Carnevale with the U.S. industry-sponsored Animal Health Institute. He says Denmark may have over-reacted.

He says, "They saw resistance. They said, 'Well, it could be due to use of drugs in animals. And certainly some of that resistance was. But the real question is, was it harming humans? And to this day, they have not been able to really conclude that it's actually harming humans."

More sick animals

Meanwhile, Carnevale adds, animals get sick more often than they did before the ban, which means Danish farmers have to use more antibiotics to treat them than they used to.

"They actually increased their uses of antibiotics quite a bit," he says. "And I don't think they got, in all cases, the change in resistance they were looking for."

A 2003 report from the World Health Organization supports Denmark's decision to ban antibiotic growth promoters. It says reducing antibiotic resistance overall is a good thing. Bacteria that become resistant can spread that trait to other bacteria. But the report notes that more data is needed about the impact on people. While researchers continue to study the issue, the debate goes on.
 

1 livestock   

n.家畜，牲畜

参考例句：

• Both men and livestock are flourishing.人畜两旺。
• The heavy rains and flooding killed scores of livestock.暴雨和大水淹死了许多牲口。

2 antibiotic   

adj.抗菌的；n.抗生素

参考例句：

• The doctor said that I should take some antibiotic.医生说我应该服些用抗生素。
• Antibiotic can be used against infection.抗菌素可以用来防止感染。

3 antibiotics   

n.（用作复数）抗生素；（用作单数）抗生物质的研究；抗生素，抗菌素( antibiotic的名词复数 )

参考例句：

• the discovery of antibiotics in the 20th century 20世纪抗生素的发现
• The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。

4 misusing   

v.使用…不当( misuse的现在分词 )；把…派作不正当的用途；虐待；滥用

参考例句：

• This means we must stop misusing them. 也就是说，我们已必须停止滥用抗菌素不可了。 来自英汉非文学 - 生命科学 - 预防生物武器
• Misusing organic fertilizer may cause a decrease in the soil's quality. 滥用有机肥料可能会导致土地的土质下降。 来自互联网

5 potent   

adj.强有力的，有权势的；有效力的

参考例句：

• The medicine had a potent effect on your disease.这药物对你的病疗效很大。
• We must account of his potent influence.我们必须考虑他的强有力的影响。

6 serum   

n.浆液，血清，乳浆

参考例句：

• The serum is available to the general public.一般公众均可获得血清。
• Untreated serum contains a set of 11 proteins called complement.未经处理的血清含有一组蛋白质，共11种，称为补体。

7 steadily   

adv.稳定地；不变地；持续地

参考例句：

• The scope of man's use of natural resources will steadily grow.人类利用自然资源的广度将日益扩大。
• Our educational reform was steadily led onto the correct path.我们的教学改革慢慢上轨道了。

8 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。