Antimicrobial resistance is a hot topic today. Studies have shown that it is spreading and starting to involve more microorganisms and antibiotics. But what is it, exactly?

Antimicrobials are any medicine designed and used to kill microscopic organisms that cause disease. The term is usually used to refer to bacteria, but it also technically includes fungi, protozoa, viruses, and parasites. However, when a microorganism survives the treatment designed to kill it, it continues to grow and pass on its resistance to its progeny. This is exacerbated by the fact that the other microorganisms that are susceptible to the drug, and die off, used to limit the growth of the resistant organisms by competition for resources. With them gone, the resistant microbe is free to spread throughout the host, unable to be controlled by modern medicines.[1]

How widespread is this problem? A Review on Antimicrobial Resistance, completed in May 2016, estimated that 700,000 people die each year from diseases that were resistant to available antibiotics. They also postulate that, by 2050, the number of deaths will increase to 10 million annually.[2]

A commonly held belief is that antibiotic use in animals is the main cause of most antimicrobial resistance. While it is true that antibiotics used to be used as growth promotants—thus exposing bacteria to low levels of antimicrobials, which they could survive and then develop resistance to—the FDA recently instituted the Veterinary Feed Directive (VFD), a program that regulates and limits the use of medically important antimicrobials.[3] What do we mean by “medically important”? Only some of the antibiotics used in food animals are the same as those used in human medicine. Because of the risk of resistance cross-over into humans, producers must consult with a veterinarian and obtain a specific prescription before they are able to use them in their herds.[4] This helps to reduce the development of resistance to antimicrobials used in humans.

Unfortunately, resistance to antimicrobials is a natural result of mutation, rapid growth and gene transfer. The same thing happens even in insecticides, and the consequences can be severe. For example, insecticides are important in the control of mosquitoes that spread malaria. However, 61 countries have reported resistance to at least one of the four classes of insecticide. Resistance is probably more widespread than this, because many countries do not perform adequate monitoring for insecticide resistance.[5]

Resistance to antimicrobials and insecticides are difficult to control, and impossible to prevent. All that can be done is to monitor for resistance, accurately gather data, learn more about the mechanisms of resistance, and develop new methods of control and prevention.[6] It’s a steadily regressing battle, as few breakthroughs have been made in antimicrobials in the past 20 years.[7]

It’s a very difficult subject to talk about considering the likelihood of such a grim outcome. But if awareness of this problem is increased, some solutions may be researched and brought to light.

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[1] https://amr-review.org/sites/default/files/160525_Final%20paper_with%20cover.pdf

[2] Ibid.

[3] https://www.fda.gov/AnimalVeterinary/DevelopmentApprovalProcess/ucm449019.htm

[4]https://www.fda.gov/downloads/AnimalVeterinary/GuidanceComplianceEnforcement/GuidanceforIndustry/UCM299624.pdf

[5] https://www.who.int/malaria/areas/vector_control/insecticide_resistance/en/

[6] Ibid.

[7] https://amr-review.org/sites/default/files/160525_Final%20paper_with%20cover.pdf