论文部分内容阅读
"Gong Xiaoming had rashes and itches. At 12：47 pm， she posted on her microblog： I ate some lamb the day before yesterday， and over the past two days I could not help but wonder that the lamb might have antibiotics？" Liao Xinbo， Deputy Director of Guangdong Provincial Health Department twittered this and replied， "Your suspicion is reasonable. The widespread use of antibiotics in animal breeding makes bacteria resistant to antibiotics， and if these bacteria spread to humans， huge problems will occur." It's a factual case reported in an article titled Antibiotics Abuse in the Breeding Industry Becomes an Open Secret--Hens， Pigs and Fish Take Medicine as Staple Food in 2011 on Nanfang Daily， one of China's authoritative media. In recent years， such doubts are frequently published on newspapers. According to statistics， there are over 20 sorts of antibiotics and some 10 strains of synthetic antimicrobial drugs used in feed. Although there are different limits on antibiotics use in animal feed currently due to health concern， cases of antibiotics abuse still occur now and then.
A miracle in the past
Antibiotics， which helped human overcome invincible bacteria， were once considered as a miracle for human race. According to Baidupedia： "Antibiotics mainly are mainly composed of bacteria， moulds or secondary metabolites or synthetic analogs produced by other microorganisms." They are primarily used to cure infectious diseases caused by microbial or disease-causing microorganism infections， and usually do not have a tangible impact on the hosts.
Like people， livestock need protein， amino acids， mineral trace elements and other nutrients to grow. Only when these nutrients are added to their feed can they grow up healthily. There are 13 categories of feed additives which are allowed in different countries such as amino acids， vitamins， minerals trace elements， etc. to protect health and control disease.
According to Qiao Shiyan， Deputy Director of China National Feed Engineering Technology Research Center， from the perspective of animal nutrition， substances added to animal feed are divided into nutritional additives and non-nutritional additives. Nutritional additives mainly refer to copper， zinc and other trace elements， while non-nutritional additives include enzymes， antibiotics （medical premix） and other additives which can improve animal health and nutrient utilization of feed additives. Among these additives， antibiotics are most closely connected with human health and the excessive use of them could cause drug residue and may transfer bacterial drug resistance genes to non-drug-resistant strains. Since antibacterial drugs were discovered in 1940s， scientists found that adding antibiotics to feed could not only promote the rapid growth of livestock and poultry， but also can drastically reduce the cost of livestock and poultry farming and the morbidity and mortality rates， bringing a revolution to the industry.
Scientists speculate that after adding antibiotics to feed， livestock nutrient uptake system will be changed， which will rapidly improve the growth rate and the weight of livestock. Its "magic effect" convinced the US Food and Drug Administration （FDA） to first approve the use of antibiotics as feed additives in 1950. Then other countries followed suit， embarking on the tour--"feeding" livestock with "antibiotics"--which reached its peak in 1970s.
A "time bomb" today
With the increasing number of cases of bacterial antibiotic resistance in the world year by year and growing data of human infected with drug-resistant bacteria in various countries， antibiotic feed was brought to the limelight and became an object of public distrust. Why has this "miracle" turned to a "time bomb" which is hated， limited and prohibited in many countries？
Since Japan detected the first case of bacterial drug resistance in 1957， safety issues related with antibiotic feed have never been out of public sight. Li Kainian from information Institute， Chinese Academy of Tropical Agricultural Science wrote in his paper-- The Role of Antibiotic Feed Additive and Its Development Trend： "When Streptomycin was used to feed turkeys in an experiment， it was put forward that antibiotic resistance may be generated in edible animals. Another report in 2002 stated that various pathogenic bacteria were already resistant to many antibiotics in the world in 1980s. "
As early as in 1997， WHO suggested that regular health management on food animal should be conducted to avoid a preventive consumption of antibiotics； antibiotics should be restricted to treatment use in accordance with prescriptions'； and the possibilities that edible animals may be the host of antibiotic resistant bacteria colony， which can be transferred to people， should be guarded against.
"Antibiotics pigs"， "antibiotics chickens"， "antibiotics fish"……" It's an era of antibiotics livestock. "Are you a vegan today？" -- The question seems to become the staple of conversation. It is even reported that using antibiotics as a panacea for preventing and treating animal disease is an open secret in the animal farming industry. Professor Xiao Yonghong， China National Key Laboratory of the Diagnosis and Treatment of Infectious Diseases， The First Affiliated Hospital of Zhejiang University， made a survey in 2006， and found that China's annual production of antibiotics was 210，000 tons， of which 97，000 tons were used for animal breeding. According to statistics， more than 13，000 tons of antibiotics are used in animal breeding in US in 2011. The purpose for farmers’using antibiotic feed additive is simple： to prevent bacterial diseases and improve farming income. One of Nanfang Daily reporter once interviewed an owner of a large pig farm. The latter said： "Without antibiotics， pigs can hardly be raised"， which showed farmers' dependence on antibiotics.
According to official studies， the direct toxicity of animal residues of antibiotics to the human body is very small， but the resistant germs can be passed to humans through air， groundwater and soil， as if it were a time bomb buried in the earth. In case of bacterial infection， the consequences would be unthinkable. Experts caution that the long-term consumption of antibiotics may cause effects ranging from mild allergic symptoms to severe cases like a variety of side effects and an enhanced human drug resistance.
Drug resistance： a killer of human health
A study conducted by the Agricultural Research Service of United States Department of Agriculture and the Michigan State University found that after adding antibiotic in pigs’feed， the pigs’drug resistance increases significantly and the pigs become "bacteria pigs". As early as in 1969， scholars from United Kingdom suggested that the world should work together to advocate the view point of "one healthiness". WHO， managers in animal health departments as well as all farming friends should pull together to combat the spread of antibiotic resistance from animals to animals or from animals to human."
For years， there have been tons of reports on antibiotic resistance. US Newsweek ran a report stating that more than 10，000 patients died of antibiotic-resistant bacterial infections in 1992. The breakout of Escherichia coli and the food poison case of salmonella were proved to be related with antimicrobial resistance of pathogens of livestock.
Mo Dihua， former vice president of China Guangdong Academy of Agricultural Science， sighed and said， "In 1960s， 400，000 units （medical units） of penicillin was enough for a pig， and now even one or two million units can only exert very little effect." With bacteria becoming increasingly drug-resistant， it takes nearly a decade to develop a new antibiotic. However， it only takes two years for the new antibiotics to lose its effect. "The growth of antibiotic resistance of pathogens around the world is an enormous challenge"， said James Tiedje， a distinguished professor of microbiology， molecular genetics， plants， soil and microbial sciences at Michigan State University.
According to related reports， 70% of China's newborns have antibiotic resistance to one antibiotic or more antibiotics. In this regard， some experts said that this was because pregnant women before pregnancy tend to eat eggs and drink chicken soup， pig's feet soup and milk and consume other poultry-related products. If animals become drug-resistant after taking antibiotics， they will also bring this resistance to the human body.
Many experts believe that the antibiotic feed may cause side effects. Qi Guanghai， deputy director of Feed Research Institute （FRI） of Chinese Academy of Agricultural Sciences believes that negative effects of long-term use and misuse of antibiotics mainly include： first， resistant problems produced by bacteria； second， declining animal immune function and increased deaths； third， the problem of drug residues in livestock and poultry products， which directly hampers human health.
A miracle in the past
Antibiotics， which helped human overcome invincible bacteria， were once considered as a miracle for human race. According to Baidupedia： "Antibiotics mainly are mainly composed of bacteria， moulds or secondary metabolites or synthetic analogs produced by other microorganisms." They are primarily used to cure infectious diseases caused by microbial or disease-causing microorganism infections， and usually do not have a tangible impact on the hosts.
Like people， livestock need protein， amino acids， mineral trace elements and other nutrients to grow. Only when these nutrients are added to their feed can they grow up healthily. There are 13 categories of feed additives which are allowed in different countries such as amino acids， vitamins， minerals trace elements， etc. to protect health and control disease.
According to Qiao Shiyan， Deputy Director of China National Feed Engineering Technology Research Center， from the perspective of animal nutrition， substances added to animal feed are divided into nutritional additives and non-nutritional additives. Nutritional additives mainly refer to copper， zinc and other trace elements， while non-nutritional additives include enzymes， antibiotics （medical premix） and other additives which can improve animal health and nutrient utilization of feed additives. Among these additives， antibiotics are most closely connected with human health and the excessive use of them could cause drug residue and may transfer bacterial drug resistance genes to non-drug-resistant strains. Since antibacterial drugs were discovered in 1940s， scientists found that adding antibiotics to feed could not only promote the rapid growth of livestock and poultry， but also can drastically reduce the cost of livestock and poultry farming and the morbidity and mortality rates， bringing a revolution to the industry.
Scientists speculate that after adding antibiotics to feed， livestock nutrient uptake system will be changed， which will rapidly improve the growth rate and the weight of livestock. Its "magic effect" convinced the US Food and Drug Administration （FDA） to first approve the use of antibiotics as feed additives in 1950. Then other countries followed suit， embarking on the tour--"feeding" livestock with "antibiotics"--which reached its peak in 1970s.
A "time bomb" today
With the increasing number of cases of bacterial antibiotic resistance in the world year by year and growing data of human infected with drug-resistant bacteria in various countries， antibiotic feed was brought to the limelight and became an object of public distrust. Why has this "miracle" turned to a "time bomb" which is hated， limited and prohibited in many countries？
Since Japan detected the first case of bacterial drug resistance in 1957， safety issues related with antibiotic feed have never been out of public sight. Li Kainian from information Institute， Chinese Academy of Tropical Agricultural Science wrote in his paper-- The Role of Antibiotic Feed Additive and Its Development Trend： "When Streptomycin was used to feed turkeys in an experiment， it was put forward that antibiotic resistance may be generated in edible animals. Another report in 2002 stated that various pathogenic bacteria were already resistant to many antibiotics in the world in 1980s. "
As early as in 1997， WHO suggested that regular health management on food animal should be conducted to avoid a preventive consumption of antibiotics； antibiotics should be restricted to treatment use in accordance with prescriptions'； and the possibilities that edible animals may be the host of antibiotic resistant bacteria colony， which can be transferred to people， should be guarded against.
"Antibiotics pigs"， "antibiotics chickens"， "antibiotics fish"……" It's an era of antibiotics livestock. "Are you a vegan today？" -- The question seems to become the staple of conversation. It is even reported that using antibiotics as a panacea for preventing and treating animal disease is an open secret in the animal farming industry. Professor Xiao Yonghong， China National Key Laboratory of the Diagnosis and Treatment of Infectious Diseases， The First Affiliated Hospital of Zhejiang University， made a survey in 2006， and found that China's annual production of antibiotics was 210，000 tons， of which 97，000 tons were used for animal breeding. According to statistics， more than 13，000 tons of antibiotics are used in animal breeding in US in 2011. The purpose for farmers’using antibiotic feed additive is simple： to prevent bacterial diseases and improve farming income. One of Nanfang Daily reporter once interviewed an owner of a large pig farm. The latter said： "Without antibiotics， pigs can hardly be raised"， which showed farmers' dependence on antibiotics.
According to official studies， the direct toxicity of animal residues of antibiotics to the human body is very small， but the resistant germs can be passed to humans through air， groundwater and soil， as if it were a time bomb buried in the earth. In case of bacterial infection， the consequences would be unthinkable. Experts caution that the long-term consumption of antibiotics may cause effects ranging from mild allergic symptoms to severe cases like a variety of side effects and an enhanced human drug resistance.
Drug resistance： a killer of human health
A study conducted by the Agricultural Research Service of United States Department of Agriculture and the Michigan State University found that after adding antibiotic in pigs’feed， the pigs’drug resistance increases significantly and the pigs become "bacteria pigs". As early as in 1969， scholars from United Kingdom suggested that the world should work together to advocate the view point of "one healthiness". WHO， managers in animal health departments as well as all farming friends should pull together to combat the spread of antibiotic resistance from animals to animals or from animals to human."
For years， there have been tons of reports on antibiotic resistance. US Newsweek ran a report stating that more than 10，000 patients died of antibiotic-resistant bacterial infections in 1992. The breakout of Escherichia coli and the food poison case of salmonella were proved to be related with antimicrobial resistance of pathogens of livestock.
Mo Dihua， former vice president of China Guangdong Academy of Agricultural Science， sighed and said， "In 1960s， 400，000 units （medical units） of penicillin was enough for a pig， and now even one or two million units can only exert very little effect." With bacteria becoming increasingly drug-resistant， it takes nearly a decade to develop a new antibiotic. However， it only takes two years for the new antibiotics to lose its effect. "The growth of antibiotic resistance of pathogens around the world is an enormous challenge"， said James Tiedje， a distinguished professor of microbiology， molecular genetics， plants， soil and microbial sciences at Michigan State University.
According to related reports， 70% of China's newborns have antibiotic resistance to one antibiotic or more antibiotics. In this regard， some experts said that this was because pregnant women before pregnancy tend to eat eggs and drink chicken soup， pig's feet soup and milk and consume other poultry-related products. If animals become drug-resistant after taking antibiotics， they will also bring this resistance to the human body.
Many experts believe that the antibiotic feed may cause side effects. Qi Guanghai， deputy director of Feed Research Institute （FRI） of Chinese Academy of Agricultural Sciences believes that negative effects of long-term use and misuse of antibiotics mainly include： first， resistant problems produced by bacteria； second， declining animal immune function and increased deaths； third， the problem of drug residues in livestock and poultry products， which directly hampers human health.