NARMS and Macrolide Resistance in Salmonella and Campylobacter

NARMS and Macrolide Resistance in Salmonella and Campylobacter

Uday Dessai¹, Ruby Singh², Sampa Mukherjee², Jovita Haro¹, Catherine Rockwell¹, Gamola Z Fortenberry¹, Bonnie Kissler¹, Sheryl Shaw¹

¹USDA Food Safety and Inspection Service
²Food and Drug Administration (FDA)

The discovery of the first antibiotic, penicillin, in 1928 and subsequent discoveries of several antimicrobial drugs provided a powerful tool to fight bacterial infections. Since then, significant advances have been made in public health to reduce the morbidity and mortality associated with infectious diseases. However, the extensive use of antibiotics/antimicrobial drugs in humans and animals has resulted in bacteria becoming resistant to the drugs that were once effective, leading to treatment failures. This phenomenon, called antimicrobial resistance (AMR), is the ability of bacteria to survive the effect of the antimicrobials used against them. Over the years, AMR has become a formidable challenge in the therapeutic use of several antimicrobial drugs, and, as a result, the pool of effective last resort antimicrobials is shrinking. Globally, public health authorities recognize the need to curb AMR as it has the potential to rapidly reverse the public health progress that has been accomplished.

To help address AMR in the U.S., the National Antimicrobial Resistance Monitoring System (NARMS), an interagency collaboration between agencies within the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA), was established in 1996. The agencies that are currently engaged in NARMS include the Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC) and the Food Safety and Inspection Service (FSIS). For almost 30 years, the NARMS program has monitored AMR in ill people (CDC), food-producing animals (FSIS), and foods (FSIS, FDA) in the U.S., and has provided a deeper insight into the multiple facets of AMR.

To protect public health, the FDA classifies certain antimicrobials as critically important (FDA Guidance to Industry #152), and macrolides is one such class of antimicrobials. The name macrolide is derived from the macrocyclic lactone ring that forms the core part of its molecular structure. Azithromycin and Erythromycin are two examples of commonly used macrolides. Given their importance in human and animal medicine, NARMS monitors bacteria developing AMR to macrolides. In a recent study published in the Journal of Antimicrobial Chemotherapy, NARMS focused on resistance to macrolides in Salmonella and Campylobacter isolated from food-producing animals, foods and humans. The study suggests that the extent of AMR to individual macrolides is growing and has the potential to show cross-resistance to other macrolides due to the commonality in their core molecular structures. Because macrolides are among the last resort antimicrobials drugs and are considered critically important, to preserve their effectiveness for the future generations, they should be used judiciously in humans and animals and carefully monitored for the development and spread of bacterial AMR.

The NARMS agencies are committed to the mission of ensuring that the effectiveness of the currently used antibiotics is preserved for people, animals and future generations alike. For additional information on NARMS, accomplishments and communications, readers can visit partner agency websites: FDA NARMS, CDC NARMS and FSIS NARMS.