Superbugs and the Animals that Create Them
Written by Lance Jimenez
Edited by Audrey Bantug
July 31st 2021
Edited by Audrey Bantug
July 31st 2021
Have you heard of superbugs? If you watch the news, the term may have been used to describe different microbes. Specifically, superbugs are microorganisms that have become resistant to multiple antibiotics. Antibiotics are designed to kill bacteria, treating and saving many people each year from bacterial diseases, so these superbugs are becoming a growing concern. Additionally, most people contribute to the rise of superbugs without even realizing it: by eating meat!
So if antibiotics are supposed to kill bacteria, how do superbugs become resistant to them? Antibiotic resistance is actually a natural response to the use of antibiotics. When bacteria are exposed to an antibiotic, most are killed, but some bacteria may have genes that let them survive. These genes grant resistance in various ways like allowing the bacteria to degrade the antibiotic or excrete them before they can work (Blair et al., 2015). These select few bacteria can now duplicate, passing this resistance to a new, more problematic generation. These resistance genes can also be spread through horizontal gene transfer, when DNA from one bacterium is passed to another bacterium (even between unrelated species!) in the same environment. With exposure to more antibiotics, these strains can develop resistance to multiple antibiotics, creating superbugs and becoming harder to treat. A means of controlling the rise of these resistant bacteria is by limiting the use of antibiotics. However, this effort is hindered by an important part of everyday life: animal agriculture.
Animal farming, especially on large scales, requires the use of antibiotics to prevent the animals from getting sick (Iwu et al., 2020). The FDA reports 11.5 million kilograms (over 25 million pounds) of antibiotics were sold for use on farm animals in 2019, with the most going to cattle, followed by pigs, and turkeys (Center for Veterinary Medicine, 2020). They are important for keeping meat safe for consumption. Unfortunately, these antibiotics and the bacteria resistant to them can be transmitted various ways to other environments. They have been detected in manure and both irrigation and fresh water sources. In turn, they can pass to crops, or back to the farm animals (Iwu et al., 2020). This makes it very likely that antibiotic resistant bacteria can find their way to humans through the food we eat.
While such an idea is troubling, limiting such occurrences is a high priority for health organizations like the World Health Organization and the Center for Disease Control. Finally, while the weight of antibiotics used for animals is in the millions, the amount used has dropped 15%, about 2 million kilograms (4.4 million pounds) since 2010 (Center for Veterinary Medicine, 2020). Bringing attention to and being mindful of this issue can greatly slow this process. To help, a simple action one person can make is eating less meat. We can slow these superbugs one Meatless Monday at a time!
References
Blair, J. M., Webber, M. A., Baylay, A. J., Ogbolu, D. O., & Piddock, L. J. (2015). Molecular mechanisms of antibiotic resistance. Nature Reviews Microbiology, 13(1), 42-51. Retrieved 14 May, 2021. https://doi.org/10.1038/nrmicro3380
Center for Veterinary Medicine. (2020, December) SUMMARY REPORT on Antimicrobials Sold or Distributed for Use in Food-Producing Animals. FDA Department of Health and Human Services. Retrieved 17 April, 2021. https://www.fda.gov/media/144427/download
Iwu, C. D., Korsten, L., Okoh, A. I. (2020). The incidence of antibiotic resistance within and beyond the agricultural ecosystem: A concern for public health. Microbiology Open, 9(9), e1035. https://doi.org/10.1002/mbo3.1035