National Antimicrobial Resistance Monitoring System – Enteric Bacteria (NARMS) Update

Recognizing the potential utility of antimicrobial susceptibility testing for monitoring trends in antimicrobial resistance development, and because of the public health concerns associated with the use of antimicrobials in food-producing animals, an antimicrobial resistance monitoring program was proposed by the Food and Drug Administration Center for Veterinary Medicine (FDA). This program was developed particularly as a post-marketing activity to help ensure the continued safety and efficacy of veterinary antimicrobials, especially fluoroquinolones. In 1996, the FDA, USDA, and CDC initiated the National Antimicrobial Resistance Monitoring System – Enteric Bacteria (NARMS) to prospectively monitor changes in antimicrobial susceptibilities of zoonotic pathogens from humans and animals. The animal arm of NARMS is located at the USDA-ARS-Russell Research Center, Athens, GA in the Antimicrobial Resistance Research Unit. Animal isolates are obtained from diagnostic (clinical submissions to veterinary diagnostic laboratories) and non-diagnostic (on-farm sampling and raw product samples collected from federally inspected slaughter and processing establishments) sources from cattle, swine, chickens, turkeys, horses, dogs, cats, and exotics. Non-typhoid Salmonella was selected as the sentinel organism. Additional organisms were added to the program, and in 2001, NARMS monitored antimicrobial susceptibility in non-typhoid Salmonella, Escherichia coli, Campylobacter, and Enterococcus originating from animals. Salmonella, E.coli, and Enterococci isolates are tested for susceptibility to a custom-made panel of antimicrobials using the SensititreTM System according to manufacturer’s directions. Campylobacter isolates are tested for susceptibility using the E-test (AB Biodisk) according to manufacturer’s directions.


The goals and objectives of the monitoring program are to 1) provide descriptive data on the extent and temporal trends of antimicrobial susceptibility in Salmonella and other enteric organisms from the human and animal populations; 2) facilitate the identification of resistance in humans and animals as it arises; 3) provide timely information to veterinarians and physicians; 4) prolong the life span of approved drugs by promoting the prudent and judicious use of antimicrobials; and 5) identify areas for more detailed investigation. Program information is available to the public and may be accessed at Additional information on results from the animal isolate testing, including percent resistance by animal species for each year testing has been conducted, can be found at


Dr. Paula Fedorka-Cray
Dr. Paula J. Fedorka-Cray received her B.S. from Penn State (Microbiology), M.S. from North Dakota State University (Bacteriology), M.A.S. from Johns Hopkins University (Administration) and a Ph.D. from the University of Nebraska Medical School (Veterinary Microbiology). She has been employed by the USDA-ARS since 1991 and is currently a Microbiologist, Research Leader for the Antimicrobial Resistance Research Unit at the Richard Russell Research Center in Athens, GA. Her program focuses on the ecology and epidemiology of antimicrobial resistance in food borne pathogens with an emphasis on Salmonella and Campylobacter. She also directs the laboratory testing efforts for the veterinary arm of the National Antimicrobial Resistance Monitoring System – Enteric Bacteria (NARMS) and she is the recipient of the FDA Commissioner’s Special Citation Honor Award for her work with NARMS.