One of the most versatile animals we domesticate today, pigs are a huge part of our everyday lives. Most households will use pig products in their homes on a daily basis, from meat to candles to soap. This has led to the growth of this fast-paced industry means that farmers are constantly trying to use and adapt the best technology and science available. When antibiotics came out in large quantities at affordable prices, many people who raised pigs in factory farming situations saw it as an effective way to ward off bacteria and keep the premature deaths of their animals to a minimum. Though this system has been working well since its introduction into the factory farming industry, there is now speculation that the excessive use of antibiotics will create super bacteria, which would be capable of spreading to humans. Countries like Denmark are being proactive about this potential issue by halting the use of over sixty percent of antibiotic use in both the poultry and pork industries. By assessing the damage that could be caused by prolonged abuse of antibiotics and studying how they could spread to humans, scientists can gain an accurate path of how to proceed effectively in the global pork industry, following the lead of countries like Denmark.
Since Darwin’s voyage on the HMS Beagle in 1831, it has been known that life exists within the boundaries of the law of the “survival of the fittest” ,which states that when a force was to act upon the population, only those who could survive that force would live to reproduce. These reproducing individuals passed on the gene that allowed for their survival to their offspring, thus keeping the trait alive in the population. Darwin, while working on the Galapagos Islands, discovered this by observing the speciation present in the finches. As Darwin noted, there were a number of finch species on the islands, and they looked very similar, save the size and shape of their bill. Bill construction is an important feature in food gathering and eating, and each of the finches had a beak suited to the food it ate. Darwin deduced that the birds all must have had a common ancestor that gave rise to the different species as niches in the environment allowed the speciation to occur. This observation was expanded, and when applied to other species and groups, lead to a better understanding of the meaning of our world’s diversity. This same phenomenon can be seen working in crop pest populations, where pesticides killed off all the insects, with the exception of those few that were genetically resistant to the chemicals. These resistant insects bred among themselves, passing on the gene of pesticide resistance to their young, thus creating new strains of pesticide-resistant insects. This same scenario can play out under a pig’s skin, with the hordes of bacteria that call it home. The antibiotics will kill most of the bacteria, but leave the few resistant ones to reproduce and populate, just as it happens to crop pests. These bacteria could potentially keep strengthening with each addition of antibiotics, and create super bacteria that cannot be killed by our current antibiotics. This would be devastating to the pork industry, as thousands of pigs would be expected to die, and much of the meat produced would become contaminated with super-bacteria, making it harmful for human consumption.
The super-bacteria that could potentially be created by the strains in the pigs would destroy the pork industry, but that may not be the limit of the potential damage.
Pigs and humans, though not very similar in appearance, have surprisingly similar internal anatomical functions and structures, due to the evolutionary links to common ancestry and the large number of shared derived traits. Because of the similarities, bacteria can jump from pigs to humans. MRSA CC398 is a bacterium that, oddly enough, started out as human-spread and human-hosted. However, it started being hosted by pigs as well, due to the close proximity of many humans to them. Now, with the excessive use of antibiotics in the trade, the bacteria has a new strain only found on pigs, and is resistant to tetracycline and methicillin, both very common and effective antibiotics. It is already well known that this bacterium is capable of spreading to humans, as it started out as human-hosted, and it is only a matter of time before it makes the trans-species host exchange a second time. Another bacterium that has had even more publicity than MRSA CC398 was the “swine flu”, also known as H1N1. Though this bacterium is not a strengthened by-product of antibiotic use, it is a common inhabitant of pigs worldwide, and, as we all found out not more than two years ago, can spread to humans given the correct conditions. By using the antibiotics so liberally, pigs are essentially functioning as petri dishes for the next worldwide human plague.
Because this issue is threatening the lives of millions of people, the country of Denmark, long known as one of the most important pork producing countries in the world, stopped the use of antibiotics for the purpose of animal growth. This radical move shocked the entire farming industry, and was responsible for a sixty percent drop in total pig antibiotic use. Many analysts feared that this move would cause the output of pork to plummet as a result, but on the contrary, it rose by over fifty percent, due to increased fertility of the female breeding stock pigs. It is expected that other countries will see the changes made my Danish Farmers and copy their methods, but some worry that the large antibiotics companies, many of which have ties with government officials, will try to make those measures difficult.
The pork industry is a worldwide industry, and brings thousands of people in direct contact with pigs every day. Because of the ability for pigs to transmit diseases to humans, we have to be proactive and make sure that our swine populations do not become a breeding ground for super bacteria. If we are not taking preemptive measures to keep the antibiotic levels in the industry to a minimum, we are setting ourselves up for disaster.
Too many, too smelly; Should Denmark's exports of pork be chopped?. The Economist [Internet]. 2003 [cited 2012 September 13]; Available from: http://www.economist.com/node/1979752
Sohn, E. Antibiotics breed drug-resistant bacteria in pigs. Discovery News [Internet], 2012 [cited 2012 September 13]; available from: http://news.discovery.com/animals/antibiotics-drug-resistant-bacteria-pigs-farming-120116.html
Vince G. ‘Pig disease' may be spreading between humans. News Science [Internet], 2005 [cited 2012 September 13]; Available from: http://www.newscientist.com/article/dn7773-pig-disease-may-be-spreading-between-humans.html
Antibiotics Prove Powerless as Super-Germs Spread. Spiegel International [Internet], 2012 [cited 2012 September 13]; Available from: http://www.spiegel.de/international/world/resistant-bacteria-antibiotics-prove-powerless-as-super-germs-spread-a-811560.html
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