Antibiotic Resistance: An Ancient Challenge

January 20, 2016



Antibiotic resistance represents a serious challenge, but that doesn’t mean it represents a new challenge. From my 20 years as a veterinarian, I share the concern about antibiotic resistance and know that the animal health community does, too. The animal health community will continue to work with all interested parties to find solutions to an issue much older than we are.

Antibiotic resistance is natural, ancient and hard-wired into the genes of bacteria. In fact, antibiotic resistant bacteria have been found in multiple places dating back tens of thousands, and in some cases, millions of years.

For example, antibiotic resistant bacteria have been found in ancient Arctic soil dated to be at least 5,000 years old. This shows bacteria have been evolving with different mechanisms to resist antibiotics even before commercial antibiotics were available. Why? Antibiotics are naturally produced by bacteria in order to decrease competition with each other for resources in the same environment and to survive.  Bacteria that have the ability to resist the antibiotics produced by other competing bacteria have an edge over the rest of the bacteria in the environment.

Another study takes a look at the microbes that are present in the intestinal tract of an isolated, uncontacted indigenous population of Yanomami Amerindians in South America.  Although these people have been isolated for over 11,000 years with no known exposure to antibiotics or western people, they harbor intestinal tract bacteria that carry antibiotic resistant genes.

Going back even further, antibiotic resistant bacteria has been found in caves that have been isolated for 4 million years.

These examples show the evolution of antibiotic resistance over time, which is also echoed by Dr. Pritish Tosh of the Infectious Diseases Department of the Mayo Clinic.

“Antibiotics are derivatives of natural compounds and derivatives of things that other organisms are already secreting and have been for millennia,” says Dr. Tosh. “Conversely, the antibiotic resistant bacteria have also existed in nature for a long time.”

Tosh notes that part of the issue is using antibiotics inappropriately and both the public health and animal health communities need to take responsibility to do a better job. He suggests steps the public can take to address the issue, including avoiding antibacterial soap and sanitizers and not expecting prescriptions of antibiotics when a doctor indicates they are not needed. Trusting your physician is a good first step.

The animal health community will continue to do our part, as well. For example, we are phasing-out use of antibiotics important to human medicine for growth promotion purposes. We are also increasing veterinary oversight by requiring a veterinary feed directive (VFD), which is essentially a prescription from a veterinarian, to treat food producing animals with antibiotics that are important in human medicine. Similar medications used in water for livestock will also move to prescription. Additionally, research is being done to find alternatives that may lessen the need for animal antibiotics in the future.

As I continue to provide information on antibiotics and the issues that impact their use, I will do my best to present information accurately and honestly and answer questions you send me. I invite you to visit our Resources Library or send me an email at I look forward to sharing what I’ve learned from 20 years as a veterinarian as we engage about animal health issues.