Integrated Surveillance for Antimicrobial-Resistance in Foodborne Pathogens of Animal Origin in Pennsylvania, 2003 — 2015

BACKGROUND: Enteric bacterial pathogens are a major cause of foodborne illnesses in the United States. Although most enteric infections are self-limiting, drug-resistant infections are associated with severe clinical outcomes. To enhance surveillance, Pennsylvania has implemented an integrated system that compares the genetic fingerprints of Salmonella from ill persons with those of Salmonella recovered from retail meat sources. METHODS: During 2003-2015, we collaborated with federal, state and academic partners to implement integrated surveillance for antimicrobial resistance in enteric bacteria.  We collaborated with the National Antimicrobial Resistance Monitoring System (NARMS) laboratories in standardized surveillance for enteric isolates from humans (CDC-NARMS) and from retail meat (FDA-NARMS).  Pennsylvania Bureau of Laboratories (PA BOL) submitted sample isolates for Salmonella, Campylobacter, E. coli O157, Shigella, and non-cholera Vibrio to CDC-NARMS. We also tested for Salmonella and Campylobacter in standard meat samples purchased from randomly selected retail outlets and submitted isolates to FDA-NARMS during 2008-2015. Federal laboratories tested clinical isolates from humans (CDC) and retail meat sources (FDA) for susceptibility to antibiotics on the NARMS panel.  PA BOL analyzed all Salmonellaisolates from clinical and retail meat sources by pulsed-field gel electrophoresis (PFGE) and developed a system for comparing patterns to facilitate early detection of outbreaks. We collaborated with federal NARMS laboratories, Pennsylvania Veterinary Laboratory, New York AG and Markets Laboratory and University of Pennsylvania clinical and veterinary laboratories in pilot studies.  RESULTS: Using molecular and epidemiologic data, we demonstrated that comparison of the genetic fingerprints of Salmonellaisolates from patients with those from meat sources can result in early detection of outbreaks. Participation in NARMS has strengthened the capacity to investigate the emergence of resistance to antimicrobial agents important for therapeutic treatment in humans and animals. Participation has provided opportunities for the laboratory to maintain proficiency in food testing, to develop improved protocols for pathogen isolation and identification, and to compare them to current protocols. Participation in FDA-NARMS retail meat surveillance has also enabled the laboratory to scale up, streamline and rapidly deploy testing procedures that would readily transfer to food testing during large foodborne outbreaks, when they occur. CONCLUSIONS: Pennsylvania’s collaboration with the National Antimicrobial Resistance Monitoring System (NARMS) laboratories in standardized surveillance for enteric isolates from humans (CDC-NARMS) and from retail meat (FDA-NARMS) has provided evidence for science-based source attribution and greatly improved the laboratory’s capacity and readiness to respond to large-scale foodborne outbreaks.