AVMA releases resources on antimicrobial resistance susceptibility testing

Veterinarians have an important role in helping protect antimicrobial effectiveness. One aspect of good antimicrobial stewardship is antimicrobial susceptibility testing (AST). This can help guide antimicrobial therapy selection and predict outcomes for bacterial infections in animals by determining the sensitivity and resistance of specific pathogens to a wide range of antimicrobial agents.

The AVMA’s Committee on Antimicrobials (CoA) recently created six documents on antimicrobial susceptibility testing to help veterinarians make quick decisions on whether and when to pursue testing for patients, be they dogs, cats, cattle, or food fish. In addition, AVMA offers an antimicrobial stewardship back-office poster and veterinary checklist for antimicrobial stewardship.

Judicious therapeutic use of antimicrobials is critically important, regardless of a patient's species, as it optimizes therapeutic efficacy, enhances treatment success, and minimizes resistance to antimicrobials. Antimicrobial resistance (AMR) threatens animal health and welfare, food production, and public health, and can impact the results of biomedical research.

Infographic depicting traditional culture vs. non-culture based methods of antimicrobial susceptibility testing (AST)
Antimicrobial susceptibility testing (AST) can help with identifying which antimicrobial regimen is specifically effective for individual patients. On a larger scale, it aids in the evaluation of treatment services provided by veterinary hospitals, clinics, and national programs for the control and prevention of infectious diseases.

“Antimicrobial susceptibility testing is arguably the most important tool that veterinarians have in determining what antimicrobial drugs can treat a presenting infection,” said Dr. Gabriel Innes, primary representative to the CoA for the American Association of Food Safety and Public Health Veterinarians (AAFSPHV).

“AST is straightforward, but not simple: although results neatly indicate the resistance profile of the tested bacteria, some antimicrobials are ineffective against certain bacteria regardless of AST results, and in some cases, AST should not be used at all,” he added.

Dr. Virginia Fajt, a clinical professor at Texas A&M University School of Veterinary Medicine & Biomedical Sciences, also helped develop the testing resources as the former lead for this project.

The AVMA supports veterinarians with a variety of educational materials and policies outlining principles for antimicrobial stewardship and judicious use. Additionally, the Clinical & Laboratory Standards Institute (CLSI), a not-for-profit organization that develops laboratory standards worldwide, has more comprehensive, detailed information provided in its “VET09—Understanding Susceptibility Test Data as a Component of Antimicrobial Stewardship in Veterinary Settings.” This document gives further information needed to successfully acquire and interpret AST results.


View the AVMA’s new Antimicrobial Susceptibility Testing Resources for Veterinarians, including a general overview and guide on non-culture–based antimicrobial resistance genetic panels in animals.

APHIS webinar covers antimicrobial resistance for veterinarians

On December 6, the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service’s (APHIS) Center for Animal Welfare presented the webinar, “Antimicrobial Resistance (AMR): The Role of Attending Veterinarians at Animal Facilities.” The webinar addressed the basics of AMR, how pets and wild animals are contributing to this global concern, and what veterinarians can do to help combat it.

About 130 attendees tuned in for the presentation, which was intended for veterinarians who work with pet breeders, exotic animal collections, and other facilities licensed under the Animal Welfare Act.

Presenters included Dr. Martha Keller, director of the Center for Animal Welfare at APHIS, and Dr. Kathryn Campitelli, kennel and small pet specialist at APHIS.

“We want to focus our efforts on preventing this in the first place as well as good antimicrobial stewardship,” Dr. Campitelli said. 

The webinar is available to view on demand. Also on the website are three one-page handouts in the Animal Care Aids section.