Scott’s preliminary results suggest that many types of disease-causing bacteria have the potential to become or already are resistant to zinc- and copper-based antimicrobial substances. Bacteria exposed to oregano oil and menthol, however, currently do not appear to readily develop resistance to these antimicrobial alternatives.

Racing for alternatives in the age of antibiotic resistance
Posted by Dr. Stephanie Pearl, Science Communicator, USDA National Institute of Food and Agriculture, on November 18, 2016 at 8:58 AM

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Alice and the Red Queen in Peter Newell’s Through the Looking Glass. Biologist Leigh Van Valen is credited for hypothesizing the need for organisms to constantly adapt and evolve by referencing the Red Queen’s race. (Illustration by Peter Newell.)
Alice and the Red Queen in Peter Newell’s Through the Looking Glass. Biologist Leigh Van Valen is credited for hypothesizing the need for organisms to constantly adapt and evolve by referencing the Red Queen’s race. (Illustration by Peter Newell.)
“This week is World Antibiotic Awareness week and ‘Get Smart About Antibiotics’ week. Learn more about how USDA works to ensure antibiotics remain effective to treat both people and animals when necessary and the alternatives available to traditional antibiotics.”

For billions of years, microbes such as bacteria and viruses have been in a struggle for survival in the face of naturally occurring antimicrobial substances. This struggle has continued in nature and into human society, where humans, plants, animals, and microbes themselves constantly ward off disease-causing microbes. The plight for adaptation and survival is not unlike the Red Queen’s race in Lewis Carroll’s Through the Looking Glass, where it takes all of the running one can do to remain in the same place.

Alexander Fleming’s accidental discovery of penicillin in the 1920s gave society a lethal weapon to protect itself against disease-causing microbes in this evolutionary race. However, with generation times often as short as 20 minutes, microbes are able to run much faster than plants and animals and take a huge lead in the Red Queen’s race. Over time, many disease-causing microbes have become resistant to penicillin and other commonly administered antibiotics, leaving society increasingly defenseless in this arms race against harmful microbes. As society continues to fight harmful microbes with the same set of traditional antimicrobial weapons, microbes continue to fight back by developing antimicrobial resistance (AMR).

To address the concerns presented by AMR, USDA’s National Institute of Food and Agriculture (NIFA) supports extramural research, education, and extension activities and complements other USDA efforts to understand and mitigate AMR along the food chain. A NIFA grantee, Dr. H. Morgan Scott, at Kansas State University studies cattle and swine to identify antimicrobial alternatives that less readily drive resistance in microbes. Scott’s preliminary results suggest that many types of disease-causing bacteria have the potential to become or already are resistant to zinc- and copper-based antimicrobial substances. Bacteria exposed to oregano oil and menthol, however, currently do not appear to readily develop resistance to these antimicrobial alternatives.

[caption id="attachment_48063" align="alignnone" width="136"]WILD OREGANO OIL WILD OREGANO OIL FROM PACIFIC HEALTH SCIENCES[/caption]

“There are no surprises here,” said Scott. “Bacteria in the environment are exposed to heavy metals at differing concentrations and have adapted to survive in various environments. But bacteria haven’t been exposed to concentrated levels of essential oils much in the past, hence why they would less readily develop resistance to these substances.”

Whatever the alternative, it is important to take into account the advantage that microbes have over humans, plants, and animals in the Red Queen’s race. “They can adapt to us more quickly than we can adapt to them,” says Scott. “That is why it is essential to minimize AMR by optimizing our use of antibiotics, using only as much as necessary.”

NIFA invests in and advances agricultural research, education and extension and seeks to make transformative discoveries that solve societal challenges.

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