Imagine cows peacefully grazing on the lawn, chewing gum, moving from place to place to pinch the green grass. This is the stage of our agricultural past, worthy of the brush of Norman Rockwell: well maintained barns, beautiful hedges, contented cows, and occasionally disturbing silence, the buzzing flies, punctuated by a slap of the tail.
And here is another picture: animals are in small, cramped metal zagonchike, sticking his head in the bowl with the corn. The dense, pungent smell of manure spreads for miles around. Cows are released on large feedlots, where they walk on bare ground and their own feces and constantly eat.
Most antibiotics produced in the US are not for humans, but for these huge feedlots of cows, pigs, chickens, and turkeys. These are modern industrial plants for fattening millions (in the case of chickens, billions) of animals for slaughter. Agronomists seek to increase meat production, including through improved nutrition – the percentage of calories turning into meat in animal food. Feeding with antibiotics is a key part of the process that ensures the growth of body fat. But at the same time it leads to increased resistance among microbes living in animals, as well as to the sediment of drugs in our food and water. This is an important, albeit ugly, analogy with what we may be doing to our children.
It is now known that resistance in humans occurs when an antibiotic kills vulnerable microbes while leaving alive those that have randomly gained resistance as a result of genetic variations. Resistant species flourish, making the subsequent courses of the drug less effective. The same thing happens on the farm, but on this issue I would like to dwell.
Bacteria, fungi and algae have been waging an endless chemical war for hundreds of millions of years. In the struggle for survival, they produce both natural antibiotics for self-defense and genes to counter their own antibiotics and those of their opponents. Thus, two sets of complex genes appeared in microorganisms: for the production of antibiotics and for resistance to them.
In 2011, scientists, analyzing the 30,000-year-old bacteria found in the Yukon permafrost, found that they are able to resist antibiotics – both natural, from mold, and semi-synthetic, having similar basic structures. This discovery was direct evidence that ancient resistance genes were widespread, long before people began to treat diseases with these drugs. The evidence of this ancient arms race shows that this phenomenon is not our fault. Or, to be more precise, not quite ours, but we have seriously aggravated it. It is not known how much order it has increased in the sphere of influence of people, but we can say that seriously. Even marine life, living among our garbage, demonstrates the resistance that human activity has caused. We leave a print everywhere.
Another consequence of the ancient origin-a simple solution to the problem can not be found. We can never completely get rid of resistance, because Darwin’s theory is correct. When a population meets a stress factor, there is a strong selection-in this case, by this criterion. And one more thing – will never manage to develop cooperativity which treats all. Microbes are too diverse, and nature constantly gives them new weapons.
Pastoral cattle yards were replaced by feedlots and giant chicken coops, where there are tens of thousands of animals. In one stable of a large industrial pig farm can live in two thousand pigs, and even more. In one henhouse – up to twenty thousand chickens. By placing them all in close, unsanitary conditions, farmers have created an excellent environment for the reproduction and spread of bacteria.
But farmers don’t feed antibiotics to animals to be able to put more healthy animals in a small space. In fact, they do not give full therapeutic doses, which are enough to treat infections. In most cases, “wards” receive food or water with a low, sub-therapeutic dose of medication to increase nutritional efficiency. This is called”growth stimulation.”
This practice began in the mid-1940s: pharmaceutical companies found that animals given antibiotics were gaining muscle mass faster. Reviewing old literature, I came across a very interesting study in 1963. It’s time to make it clear (at least for me), but even then the nature of the interaction of intestinal microbes and antibiotics was described! Scientists have asked themselves what causes the observed effects of animal growth stimulation: antibiotics themselves (which affect tissues) or changes in the microbiome (or, in their terminology, “normal flora”), which are caused by drugs. To do this, they raised two groups of chickens: in normal conditions, or, as we say, “conventional”, and sterile, no microbes at all. In each group, half of the animals received antibiotics, and the other – the control group – did not receive.
As expected, chickens grown in conventional ways and exposed to small doses of antibiotics have grown larger. But both groups “amicrobic” presented a surprise: chickens grew the same. This suggests that the key role played by microbes living in the body; by themselves, the antibiotics are ineffective. This discovery was made fifty years ago, but it was ignored and then completely forgotten.
Today, 70-80 % of all antibiotics sold in the United States are used exclusively for fattening farm animals: hundreds of millions of cows, chickens, turkeys, pigs, sheep, geese, ducks, goats. In 2011, animal breeders bought nearly 30 million pounds of drugs-the largest amount in history. We don’t know the exact numbers because it’s a closely guarded secret. Both the agricultural and pharmaceutical industries are trying to hide their methods.
The consequences were obvious: farmers quickly realized that animals could gain 5 to 15% more weight than usual, at a relatively low cost. That, in fact, happened. It’s called improving the efficiency of supply. Pharmaceutical companies have found that they can make big profits by selling tons of drugs to farmers, not milligrams to doctors.
According to the former Chairman of the us food and drug Administration, David Kessler, until 2008, the Congress did not require pharmacists to report on the number of medicines sold to agriculture. Not information about how the amount of given medicine which animal and why. Lobbyists have successfully managed to block most attempts to reduce their use. Because of this long-running battle, there is little research on the merits and demerits of stimulating growth. With the exception of a few scientists working in these industries, few pay attention to this problem.
At the same time, environmentalists and doctors are very unhappy with the practice of stimulating growth, noting that farmers give animals the same drugs that doctors prescribe to people. In 2013, the us consumer Union conducted tests on pork carcasses and found that 13 of the 14 Staphylococcus samples found in pork were resistant to at least one antibiotic. As well as 6 of the 8 Salmonella samples, and 121 of the 132 Yersinia samples. In one carcass, and is found MRSA. Why are we throwing precious medicines around to make a pound of meat cheaper by a few cents? Including those who save lives when nothing helps.
In 2011, more than half of samples of beef and Turkey meat, and pork chops taken from supermarkets for testing contained a similar bacteria – sometimes called “supermicron”. In fact, there are no” super-microbes”, this term is invented by journalists. But if any attack on your knee or heart valve, and none of the antibiotics will help, you will surely believe that he has “inhuman” abilities.
Resistance is not the only problem. The national antimicrobial monitoring system (a joint project of the food and drug administration, the Ministry of agriculture and the Centers for disease control and prevention) found in 87% of meat samples from supermarkets either normal or resistant forms of Enterococcus bacteria – a sign of faecal contamination. Two types – Enterococcus faecalis and Enterococcus faecium – are the main causes of infections in intensive care units of American hospitals. It is possible that some patients received them from food.
Sweden banned the use of antibiotics to stimulate growth in 1986, the European Union in 1999. That is, since then, the use of any antibiotics to stimulate growth in animal nutrition has been banned throughout Europe.
American food and pharmaceutical companies claim that there is no concrete evidence that resistant microbes from animals infect humans. In fact, for more than thirty years there is evidence that the same organism with the same antibiotic resistance properties manifests itself in both humans and animals fed antibiotics to stimulate growth. For example, more than two thousand different strains of Salmonella have been typed and given their own names – we know them. Epidemics of diseases that cause Salmonella have long been associated with the activities of industrial farms. Microbes isolated from animals, food and infected people have identical molecular profiles and resistance properties.
Such obstruction runs counter to common sense and exemplifies a libertarian policy of non-intervention that is detrimental to the health of the nation. Bacteria do not respect political dogmas and do not recognize borders and jurisdictions. In March 2013, Danish scientists gave us another piece of evidence. Using complete genomic sequencing, the researchers showed that the cause of MRSA infection in two Danish farmers was the same organism that infected their animals-it could not happen by accident. So that this fact is proof that they were infected by this strain when in contact with animals.
to be continued…