Non-typhoidal Salmonella enterica is widely dispersed in nature. It can be found in intestinal tracts of vertebrates including wildlife, livestock, domestic pets, and also in environmental sources such as pond water. It is spread through the fecal oral route and through contact with contaminated foods. An estimated 1.2 million people get sick from Salmonella infection in the United States each year. Of these, about 23,000 are hospitalized, and 450 die from their infections. Symptoms include nausea, vomiting, abdominal cramps, diarrhea, fever, headache generally lasting 4 to 7 days with acute symptoms lasting 1-2 days. Serious disease can develop in the very young, the elderly and the immunocompromised. Fluoroquinolones and cephalosporins are used as first-line therapies for the treatment of serious Salmonella infection in adults. Cephalosporins are recommended for the treatment of pediatric infections. More information can be found in FDA’s Bad Bug Book.

Campylobacter is part of the natural gut flora of most food-producing animals such as chickens, turkeys, swine, cattle and sheep. It is estimated to cause over 1.3 million illnesses and 76 deaths in the United States each year. More than 80% of Campylobacter infections are caused by C. jejuni. However, other Campylobacter species, such as C. coli and C. fetus can cause disease in humans. C. coli and C. jejuni cause similar disease symptoms including fever, diarrhea, abdominal cramps, and vomiting lasting anywhere from 2 to 10 days. Most cases of Campylobacter gastroenteritis are self-limited and typically, antibiotic therapy is not needed. When antibiotic therapy is indicated, macrolides and fluoroquinolones are most commonly prescribed. Major food sources linked to C. jejuni infections include improperly handled or undercooked poultry products, raw milk and cheeses made from raw milk, and contaminated water. More information can be found in FDA’s Bad Bug Book.

Escherichia coli (E. coli) is one of the predominant enteric species in the normal intestinal flora of vertebrates. However some serotypes of E. coli can cause severe diarrheal diseases in humans. One of these pathogenic strains is E. coli O157, which is monitored for antibiotic resistance by CDC in the human population. More information can be found on the CDC website. USDA and FDA monitor resistance among generic (non-serotyped) E. coli from food animals and retail meats. Generic E. coli are used by NARMS as an indicator organism to detect both emerging resistance patterns and specific resistance genes that could potentially be transferred to other pathogenic gram negative bacteria, like Salmonella.

Enterococcus is ubiquitous in nature and can be found in the gastrointestinal tracts, genitourinary tracts, oral cavities, and skin of humans and animals, as well as in insects, plants, soil, and water. Enterococcus is the only gram positive organism that NARMS routinely monitors. Because it is consistently present in both meats and food animals, NARMS uses Enterococcus as an indicator organism to track resistance to antibiotics with activity against gram positive organisms that may result from antimicrobial use. Enterococcus infection is notable largely as a hospital or community-acquired illness, and not much information is known about its role as a direct cause of foodborne illness. However, it is known that poorly processed meat and milk are among the foods that can transmit it. More information can be found in FDA’s Bad Bug Book.

The FDA's Center for Veterinary Medicine is responsible for the regulation of antibiotics used in animals, including animals raised for food. The FDA arm of NARMS provides data about resistance in bacteria isolated from retail meats. This is important, because these data represent the major route of human exposure.

FDA uses NARMS to:

• understand how resistance emerges, persists, and spreads;
• support risk analysis of foodborne antimicrobial resistance hazards when evaluating a new animal antibiotic for safety;
• help understand the nature and magnitude of antibiotic resistance trends;
• help guide evidence-based action to limit or reverse worsening antibiotic resistance trends;
• measure the impact of new FDA policies and regulations that relate to the use of antibiotics in animal agriculture;
• assist USDA and CDC with outbreak detection.

NARMS supports the FDA regulatory mission 

• FDA first used NARMS surveillance results to address an adverse resistance trend in the early 2000s in response to data showing a rapid increase in fluoroquinolone-resistant Campylobacter, a major foodborne pathogen. In 2005, FDA undertook a lengthy legal process that resulted in withdrawing the approval for fluoroquinolones in poultry, a major source of Campylobacter infection. Since this action, resistance has stopped increasing, but has not declined to levels seen before these compounds were approved in the late 1990s. This is an example of an intervention that stopped, but did not reverse, a worsening trend. NARMS continues to watch this situation and highlight it in its annual reports.
• NARMS observed increasing resistance to extended-spectrum cephalosporins (ESC) among certain strains of Salmonella. Because this class of drugs is vital for treating Salmonella infections, resistance to these compounds is considered a significant threat to human health. In response, the FDA issued an extra-label (unapproved) use prohibition, which prohibited certain uses of ESC in cattle, swine, chickens and turkeys. Specifically, the prohibited uses include using ESC at unapproved dose levels, frequencies, durations, or routes of administration; using ESC in cattle, swine, chickens or turkeys that are not approved for use in that species (e.g., ESC intended for humans or companion animals); and, using ESC for disease prevention. This regulation went into effect in April of 2012.
• In December 2013, the FDA announced plans to end the long-term practice of administering medically important antibiotics to food producing animals for promoting animal growth and increasing feed efficiency, practices based on economic efficiency rather than medical necessity. This judicious use strategy is part of the agency’s multipronged approach to preserving the power of antibiotics for treating infectious diseases in humans and animals. By tracking resistance to the antimicrobial compounds affected by this policy, NARMS will play a role in measuring the strategy's impact on overall resistance in foodborne bacteria.

CDC NARMS helps protect public health by providing ongoing surveillance of enteric bacteria causing antibiotic resistant infections in people. CDC scientists track antibiotic resistance and study emerging resistance in bacteria that infect people commonly through food. The CDC arm of NARMS provides data about resistance in both sporadic cases and outbreaks. Investigations of outbreaks of resistant enteric infections provide data about the sources of both sporadic and outbreak-associated infections.

Preventing enteric (intestinal) infections caused by food and other sources reduces both antibiotic-susceptible and antibiotic-resistant infections.

CDC helps protect public health by using NARMS data to:

• detect and track resistant infections;
• study how resistance emerges and spreads;
• estimate how many resistant infections occur in the United States;
• determine the health impact of resistant infections;
• determine the sources of resistant infections;
• improve antibiotic prescribing and use;
• educate consumers and industry about food safety; and
• prevent infections.

The Food Safety and Inspection Service (FSIS) is the public health agency in the U. S. Department of Agriculture (USDA) responsible for ensuring that the nation’s commercial supply of meat, poultry (e.g., young chickens and turkeys), and egg products (e.g., liquid eggs) are safe, wholesome, and properly labeled. Within the FSIS mission, the agency examines the hazards and risks associated with FSIS-regulated products to reduce human exposure to foodborne pathogens and prevent foodborne illness. As such, FSIS collaborates with the USDA Animal Plant Health Inspection Service (APHIS), USDA Agriculture Research Service (ARS), FDA, and CDC to monitor and characterize foodborne pathogens and bacteria isolated from humans and animals to identify patterns of resistance in antibiotics of human health concern through the NARMS program.

FSIS uses NARMS data to:

• increase scientific knowledge regarding the emergence, persistence, and spread of antimicrobial resistance among foodborne bacteria;
• evaluate potential associations between antimicrobial resistance in preharvest, postharvest and other production settings in collaboration with other USDA agencies;
• communicate the significance of PFGE patterns, serotypes, and AST results to industry on a case by case basis;
• support hypothesis generation during outbreak investigations;
• continuously evaluate and seek to understand and employ new or innovative mission-supporting processes, methodologies, and technologies; and
• collaborate with other USDA agencies to develop an action plan for a comprehensive, integrated approach for future surveillance, research and development, and education and outreach activities.