The potential use of penicillin as a medical treatment was only realized years after its discovery. Although known as the ‘miracle drug’ in medicine, it has also proven to have some ‘miraculous’ benefits in the animal husbandry industry.
In the early 1940s, food shortage became an increasing concern. With the discovery of penicillin, the livestock industry found that if they provided low doses of antibiotics to animals, it would make them grow up to 3% of body fat with the same amount of feed. This, of course, was eventually seen as the most economically efficient way to farm animals, allowing animal producers to increase yield and increase the profit from each animal. Antibiotics also helped maintaining the health of the livestock, as the drugs could be used both to prevent and treat animal diseases. And because antibiotics worked so well, livestock could be reared at higher densities in tighter quarters and poor sanitary conditions without fear of infections spreading through the herd, enabling profits to be maximized. The video below is a great example of how antibiotic resistance is developed through these mechanisms of farming.
Over 80% of the antibiotics used in the United States of America are used in farm animals, primarily for non-therapeutic purposes. It seems clear why the food industry has received a lot of criticism and skepticism from the public, as concern grows about the way animals are treated on farms and about the provenance of food – some have even become vegetarian. UK Chief Medical Officer, Dame Sally Davies shares, “If you eat meat and fish, then you would want to know that a third of the countries globally use antibiotics instead of hygiene as a cheap way to fatten meat and fish up, isn’t it horrible?”
Many of the antibiotics that livestock industries use in animal production are very similar to the ones that are used in humans, which we know ultimately increases the exposure to antibiotics, and thus eventual resistance, through natural evolution and gene sharing mechanisms that bacteria use to survive. How does something like this pose a threat to human health?
Just as the video indicates, the antibiotic resistant bacteria could travel to our water sources, into the soil and into the air, as well as being present in the meat. Increasingly, studies show high levels of antibiotic resistant bacteria in pigs and other livestock, and it is known that people with high levels of contact with livestock, such as farmers and vets are more likely to carry antibiotic-resistant bacteria and have a higher risk of infections with resistant strains of bacteria. In addition, microbiological surveys of retail meat also show increasing levels of contamination of these products with antibiotic-resistant bacteria. The contamination of soil by antibiotic resistance bacteria may also affect plant-based agriculture, since animal manure is used as plant fertilizer. Use of low-dose antibiotics in animals promotes the development of antibiotic resistance, and animals can shed resistant bacteria in the faeces, and manure is often used as plant fertilizer.
How does society address the complex issues surrounding something like antibiotic resistance? Is it necessary for groups of people to be blamed for this? How do we move forward from a growing concern this fast and this big? How did we get this far?
“Well nowadays, antibiotic resistance should come on to the world global agenda, which means that not only as a doctor, invested in antimicrobial resistance, but the patients are invested, the trade systems are invested, the industries are into it, economy, human rights, food environment, you know food animal today growing because we are using antibiotics to make them grow, or antibiotics make them grow faster, so it is really becoming a global health issue. And if I tell you that, today you can only give some antibiotics to animals and you may reserve antibiotics to humans you would find it normal but this is not the case.”
Prof. Didier Pittet ICPIC Chair
International Conference on Prevention & Infection Control (ICPIC)
In coming blog posts, we will explore some of the potential ways in which these problems could be addressed. But we should not underestimate the impact that the private sector can make. Multinational corporations have a huge influence on the structure and practices of agriculture and food production. Notably, McDonald’s has recently announced that it will shift to using chickens that are not raised with antibiotics over the course of 2 years. The hope is that this will also provide pressure for competitors in the fast-food chain industry to follow suit.
Another sphere in which antibiotic resistance has been an increasing concern is in many of the common household products that we use. Antibacterials can nowadays be found in products that claim to kill bacteria, including soaps and households cleaning agents, toothpaste, toys, plastic kitchen tools, cutting boards, highchairs, bedding and other fabrics. These chemicals have been found to be useful disinfectants in health care settings where there is high risk of infection, but there has been no evidence to show that they provide additional health benefits outside the clinical setting. Recent laboratory evidence has shown that bacteria can develop resistance to antibacterial substances such as triclosan, and that the mechanisms that lead to triclosan resistance could also help bacteria become resistant to commonly used antibiotics such as chloramphenicol, ampicillin, tetracycline and ciprofloxacin.
Although it is unclear how much these antibacterial products contribute to antibiotic resistance, many scientist believe that widespread use of these products is dangerous, because it increases the risk of antibiotic resistance while providing no health benefits. There is also the risk that these products give people a false sense of security, possibly leading them to become more relaxed in their hygiene and sanitation habits and neglect proven hygiene practices like proper handwashing. In addition, it is possible that these products could disrupt normal bacterial flora in the body that act as barriers against pathogens, which may increase our susceptibility to resistant bacteria.
For most hygiene and sanitation purposes, regular soap and rinsing with running water would suffice. This is important when doing any routine activity such as using the toilet, changing a diaper, emptying a diaper pail, cleaning the toilet, or after handling raw meat or poultry. Other effective, commonly known household disinfectants are (70% of) ethyl, isopropyl alcohol and hydrogen peroxide.
Antibiotic use has clearly been rampant in our society with everything that we touch and consume. How does this excessive exposure to antibiotics affect our livelihood? How much of this exposure causes resistance in bacteria? Is there hope to overcome this issue?
We will continue exploring these issues as we near the end of World Antibiotic Awareness Week.