National Antimicrobial Resistance Monitoring System (NARMS)

The National Antimicrobial Resistance Monitoring System (NARMS) is an interagency, collaborative partnership with state and local public health departments, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and the U.S. Department of Agriculture (USDA).

This national public health surveillance system tracks changes in antimicrobial susceptibility of select foodborne enteric bacteria found in ill people (CDC), retail meats (FDA), and food animals (USDA). The NARMS program at USDA focuses on two sampling points—samples collected from intestinal (cecal) content and carcass or food commodity samples.

FSIS National Antimicrobial Resistance Monitoring System Cecal Sampling Program, 2014 Salmonella Report

Primary Objectives of NARMS

Monitor trends in antimicrobial resistance among enteric bacteria from humans, retail meats, and animals.
Disseminate timely information on antimicrobial resistance to promote interventions which reduce resistance among foodborne bacteria.
Conduct research to achieve better understanding of emergence, persistence, and spread of antimicrobial resistance.
Provide data that assists FDA in decision making involving the approval of safe and effective antimicrobial drugs for animals.

Data Collection

FDA, CDC, and USDA collect data from farm to fork to accomplish the NARMS objectives. These data are collected from three sources:

Figure 1. Transition of NARMS Program at USDA

Food Animal Component

In 1997, NARMS began collecting data on food animals which was led by the USDA Agriculture Research Service (ARS) through 2013. Antimicrobial susceptibility testing (AST) for non-typhoidal Salmonella began in 1997 on isolates collected from raw meat and poultry products at all slaughter facilities across the United States under the Pathogen Reduction Hazard Analysis and Critical Control Point (PR/HACCP) program. Sample types have changed over the years depending on FSIS directives: carcasses of cows/bulls, steers/heifers, market hogs1, broilers (young chickens), ground beef, ground chicken and ground turkey. Testing later expanded to include Campylobacter (1998), E. coli (2000), and Enterococcus (2003) isolated from chicken carcasses.

ARS discontinued AST of Enterococcus in PR/HACCP chicken isolates in 2012 and E. coli in 2013. Those organisms are currently tested from food animal ceca and retail meat samples. In October 2013, FSIS assumed responsibility for the AST of NARMS PR/HACCP isolates.

In March 2013, NARMS began the cecal sampling program—a collaborative effort between the FDA's Center for Veterinary Medicine (CVM) and FSIS. Samples from cecal contents are collected at slaughter facilities of selected food animals and analyzed for Salmonella, Campylobacter, Escherichia coli, and Enterococcus. The food animals that are sampled include young chickens, young turkeys, dairy cattle, beef cattle, market hogs, and sows.

In 2014, the FDA began whole genome sequencing (WGS) on Salmonella isolates collected from the cecal program. Today, FSIS performs WGS on all Salmonella and Campylobacter isolates collected from both the PR/HACCP and cecal programs.

Retail Meat Component

In 2002, NARMS began collecting retail meat samples. This component is led by FDA’s Center for Veterinary Medicine (CVM). Retail meat surveillance is conducted in 18 states in partnerships with universities and public health departments. Participating sites purchase chicken, ground turkey, ground beef, and pork chops at retail outlets and culture them for nontyphoidal Salmonella and Campylobacter. Additionally, 11 sites also culture retail meats for E. coli and 9 sites culture for Enterococcus. Additional information on FDA NARMS is available at https://www.fda.gov/AnimalVeterinary/SafetyHealth/AntimicrobialResistance/NationalAntimicrobialResistanceMonitoringSystem/.

Human Component

In 1996, NARMS began collecting antibiotic resistance data from ill people on select enteric bacteria transmitted commonly through food. This component started within the framework of CDC’s Emerging Infections Program and the Foodborne Diseases Active Surveillance Network (FoodNet). Human surveillance began in fourteen sites in 1996 and became nationwide in 2003. CDC performs AST on approximately 5000 human isolates per year. Additional information on CDC NARMS is available at https://www.cdc.gov/narms.

NARMS Reporting

Each year, NARMS publishes an Annual Integrated Report that summarizes the most important resistance findings from the three participating Agencies for Salmonella and Campylobacter, as well as for E. coli and Enterococcus. This report includes summary data tables, isolate level information and interactive Tableau displays to enhance data visualization.

Antimicrobial Susceptibility Testing

The antimicrobial drugs selected for testing are based on their importance in human and veterinary medicine and for their utility as epidemiological markers for the movement of resistant bacteria and genes between environments. NARMS partners test for bacterial susceptibility to a range of antimicrobial drugs which include 15 antimicrobial drugs for Salmonella and E. coli, 9 for Campylobacter and 16 for Enterococcus. Selected antimicrobials/antimicrobial drug classes are also ranked, by FDA, as Critically Important, Highly Important and Important using similar criteria. The specific factors and the criteria to rank the importance of antimicrobial drugs are outlined in FDA’s Guidance - GFI #152.

Whole Genome Sequencing

Whole genome sequencing (WGS) technology has become a routine part of NARMS surveillance to screen for resistance genes in enteric bacteria. Use of WGS can provide better isolate resolution including resistance genes and mobile elements and help link human and non-human resistance data.

*Note: The FSIS NARMS report gives a description of antimicrobial resistance surveillance data in certain foodborne pathogens and assists the Agency and NARMS partners in making food safety and policy decisions. FSIS recommends that consumers keep their food safe and reduce the chance of illness at home by practicing four simple food safety tips: clean, separate, cook, chill.