Antibiotics,Toxins in food chain -- Vegetables, Resistance -- various

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12 July 2007

Antibiotics Absorbed By Vegetables

 

Evaluating the impact of livestock antibiotics on the environment, University

of Minnesota researchers have found that many vegetables uptake the antibiotics.

The study, in the Journal of Environmental Quality, shows that food crops can

readily accumulate antibiotics from soils spread with cattle manure.

The findings were based on a greenhouse study involving three food crops:

corn, lettuce, and potatoes. The plants were grown in soil modified with liquid

hog manure containing sulfamethazine, a commonly used veterinary antibiotic. The

researchers found that the antibiotic was taken up by all three crops. The

antibiotic was found in the plant leaves and concentrations in the plant tissue

increased as the amount of antibiotic present in the manure increased.

Worryingly, it also diffused into potato tubers, which suggests that other root

crops - such as carrots and radishes - may be particularly vulnerable to

antibiotic contamination. Researcher Satish Gupta said that contaminated

plants had the potential to cause allergic reactions in people with antibiotic

sensitivity. He also noted that contamination is likely to foster antimicrobial

resistance, which can render antibiotics ineffective. And co-researcher Holly

Dolliver warned that antibiotic contaminated plants may be

of particular concern to the organic farming industry, where manure is often

the main source of crop nutrients. While the USDA stipulates that organic

producers must manage animal materials in a manner that does not contribute to

contamination of crops by residues of prohibited substances, manures containing

antibiotics are not formally banned or prohibited. Dolliver concluded that

further research is needed to investigate how different plants absorb different

antibiotic compounds.

http://www.scienceagogo.com/news/20070611194357data_trunc_sys.shtml

Source: Soil Science Society of America

 

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Researchers find animal antibiotics in vegetables

 

By Ahmed ElAmin

 

11/22/2005 - Antibiotics given to livestock can end up in vegetables and pose a

health threat to consumers, according to a study looking at the use of animal

manure as a fertilizer.

 

 

The University of Minnesota study will add to the level of public concern

about the food the eat. It also serves as a warning to food processors that they

need to be vigilant when sourcing their vegetables.

The processing industry is under regulatory and consumer pressure to ensure

the safety of their food products. Regular breakdowns in food safety and reports

on contamination have raised consumer awareness about the problem.

The study, published in the Journal of Environmental Quality, indicates that

processors will have to be careful when sourcing their vegetables, whether

non-organic or organic. The contaminationthreat is due to the US laws allowing

farmers to use animal manure as fertilizer in both conventional and organic

agriculture.

In the study, University of Minnesota researchers found that corn, cabbage,

and green onions absorbed chlortetracycline from manure fertilizer obtained from

pigs that were given the antibiotic.

Chlortetracycline is a member of the tetracycline class of antibiotics that

are used in human medicine to treat upper respiratory tract infections and other

illnesses. Tetracyclines and otherantibiotics also are used as feed additives in

poultry, hogs and beef cattle.

Feed additives are not used to treat disease, but to promote slightly faster

growth and to compensate for overcrowded and unsanitary conditions on

industrial-scale farms.

When the antibiotics are ingested by a human they can spur the bacteria

naturally present in the intestinal tract, including types of bacteria that can

cause serious disease, to becomedrug-resistant, the researchers stated.

" Vegetarians may think the huge overuse of antibiotics in livestock and

poultry will not affect them, but that's not true for two reasons, " stated

Margaret Mellon, the director ofthe Union of Concerned Scientists' Food and

Environment Program. " Consumers eating vegetables grown on soil fertilized with

manure may be unknowingly ingesting antibiotics. Even moreimportantly, resistant

bacteria that are created on the farm can contaminate air, water and soil that

can travel significant distances. "

While raw and composted manure may be used with little restriction in

conventional agriculture, the US Department of Agriculture's rules requires that

manure used in organic farming be composted orbe applied at least 90 days before

harvest. In the study, the crops were harvested within only 42 days, so the

findings may not apply to organic vegetables, the researchers stated.

Demand for organic foods has increased by almost 17 per cent over the past

year, according to a report this week by Whole Foods Market. The latest survey

commissioned by leading organic supermarketreveals that about two-thirds of the

US' consumers bought organic goods in 2005, compared to just over half in both

2003 and 2004.

According to the Organic Trade Association's 2004 manufacturers' survey, the

organic foods industry had $10.8 billion in revenues in 2003 and has grown at an

average rate of 19.5 per cent per yearsince 1997.

Market researcher Euromonitor predicts that sales of packaged organic foods

alone will be worth $8.6 billion at retail by 2009 - up from 5.1 billion in

2003.

Most of the participants said they opt for organic goods in order to avoid

pesticides, for their freshness, for their nutritional benefits and in an effort

to avoid genetically modified foods.

A majority of consumers also felt organic products were of better quality, as

well as being better for the health and the environment.

http://www.nutraingredients-usa.com/news/ng.asp?n=64069-antibiotics-organic-manu\

re%20

 

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21 July 2005

Prevalence Of Antibiotic Resistance Surprises

 

It's widely accepted in the medical community that a high level of antibiotic

use is related to antibiotic resistance, but only recently has the risk to the

individual been assessed. The study, published in the Journal of Antimicrobial

Chemotherapy this month, and funded by the British Society for Antimicrobial

Chemotherapy, has shown that patients who have taken a prescription of

antibiotics within the previous two months have double the chance of carrying

antibiotic resistant bacteria. The same effect was not seen in patients who had

taken a prescribed course of antibiotics within the previous 12 months. The

study's findings indicate that despite patient expectations, doctors should be

more discerning when prescribing antibiotics.

The study looked at whether a doctor prescribing antibiotics increased an

individual's risk of developing antibiotic resistance. Previous research has

shown that antibiotics are often prescribed for minor ailments where they have a

limited or insignificant effect. In spite of this, a culture of antibiotic use

seems to have evolved, where patients seeing doctors with sore throats, coughs

and ear-ache expect to be treated with antibiotics. Dr Alastair Hay, from

Bristol University said: " Although GPs [doctors] are aware of the problem in the

population as a whole, when deciding whether or not to prescribe antibiotics for

an individual they may consider the risk as being minimal. " Bacterial

resistance was tested in organisms from urine samples submitted by 3,000 adults

without urinary symptoms. The urinary E. coli bacteria found in low

concentrations were defined as resistant if they demonstrated resistance to the

antibiotic amoxicillin or the antibiotic trimethoprim, or

both antibiotics. The results showed that antibiotics prescribed in the 12

months prior to obtaining the urine sample did not influence the resistance of

organisms - presumably because the time period in question is too long. However,

the more recent use of antibiotics - within 2 months - led to a near doubling of

the likelihood of resistance. The team also found that over a 12-month period

prior to sampling, each additional tablet of trimethoprim (200mg) prescribed

increased the chances of developing resistance. In addition, the degree of

resistance to amoxicillin was greater in patients prescribed any penicillin

antibiotic in the 12 months prior to urine sampling. While the research is

only preliminary, the initial results indicate that both patients and doctors

should be aware of this information when deciding whether to prescribe and

consume antibiotics.

http://www.scienceagogo.com/news/20050620232026data_trunc_sys.shtml

 

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Researcher seeks food chain toxin tests

The Associated Press

Article Launched: 07/12/2007 12:09:19 PM PDT

 

 

 

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10px " ; } WASHINGTON—Tests that

determine whether toxic chemicals accumulate in food may be missing some

hazardous materials and need to be updated, a Canadian researcher said Thursday.

It has long been known that toxins can accumulate in the food chain, rising to

higher concentrations as larger animals eat smaller ones. But current tests

for this accumulation focus on foods of aquatic origin, Frank A. P. C. Gobas, an

environmental chemist and toxicologist at Simon Fraser University in British

Columbia said in a telephone interview. Researchers have found there are

chemicals that do not accumulate in fish, but which do so in air-breathing

animals, such as mammals, Gobas reports in a paper in

Friday's issue of the journal Science. Bioaccumulation testing is done in the

same way in most countries, Gobas said: " We're all basically making roughly the

same mistake. " He said testing must be updated to cover chemicals that do not

accumulate in marine life but may do so in air-breathing animals because of

their slow rate of elimination during respiration. Gobas said he has been

studying the food chain of animals in the Canadian arctic where caribou eat

lichen and wolves eat caribou. He said he found increasing accumulations of

potentially toxic chemicals moving up that food chain, though the same chemicals

did not accumulate in marine life. Further study found the same in other

animals. Was he surprised? " Well, you're always surprised, of course, but in

hindsight I should not have been. It made us think about the process in a

different way, " he said.

——— On the Net: Science: http://www.sciencemag.org

 

 

http://www.mercurynews.com/healthandscience/ci_6359103?nclick_check=1

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24 February 2006

Prof Ponders Bacterial Benefits

 

Destroy all bacteria, bacteria are bad; goes the mantra of mothers everywhere

and the cleaning product industry. But they could be incorrect, says Stanford

University microbiologist Stanley Falkow. In an essay in the latest issue of the

journal Cell, he canvases the intriguing idea that persistent bacterial and

viral infections may have very real health benefits.

" Organisms that cause disease are usually considered in the context of harm

and epidemics and so on, " explained Falkow. " But the fact is that a great number

of organisms that infect humans come in and set up housekeeping as it were.

There are no clinical symptoms of anything wrong and people take the organisms

with them to their graves. " Falkow is quick to point out that it's not that the

organisms in question - such as the bacteria that cause pneumonia or meningitis

- are harmless, but that most individuals do not contract a disease from being

infected. Falkow cites the example of H. pylori, which was implicated as a

cause of ulcers and stomach cancers by last year's Nobel Prize in Medicine

winners. As clean water and pasteurization are adopted in developing nations,

the prevalence of H. pylori infection has declined. Understandably, this has

been accompanied by a drop in the incidence of gastric cancer and ulcers. But

intriguingly, there has been an increase in

esophageal cancer. Could H. pylori be protecting against cancer of the

esophagus? Is it possible that " there might be something about persistent

infection that might be protective, " wonders Falkow. Falkow and fellow

researchers have been studying the phenomenon of persistent infection for

decades, in particular with H. pylori and Salmonella. They have shown that when

infected with these organisms, mice initially show an inflammatory response that

then settles down and stays with them for the rest of their lives. Although very

few of these organisms remain in the mice, it's enough to cause the immune

system to have an ongoing response. " It's not so much that the immune system has

failed, " Falkow explained, " but that the organisms have manipulated the immune

system in such a way that they can't be cleared. " If the infections are cleared

by antibiotic intervention, the mice are highly susceptible to re-infection, and

the re-infection is more likely to progress to disease

than the initial infection. " The continued presence of these organisms in

human society may actually be beneficial to the host, and that is why they are

tolerated by the immune system, " said Falkow. " We can guess that since a

persistently infected host is constantly having its immune system stimulated and

refined, that may provide it with resistance to other things. " The fact that a

decrease in infectious diseases over recent years has been accompanied by a rise

in autoimmune diseases, such as diabetes, lends weight to the idea that we may

be wrong-headed in our thinking about bacteria. As with H. pylori, Falkow

wonders whether humans are unknowingly causing the disappearance of other things

that have been with us for all of our evolution, and that may well play some

role in our health. He believes that further research with animal models may

provide answers. Source: Stanford University Medical Center

http://www.scienceagogo.com/news/20060123233523data_trunc_sys.shtml

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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