Purpose: To determine the prevalence of Salmonella and antibiotic resistant Campylobacter in ground beef at retail across the United States.
Methods: A total of 96 ground beef samples were collected from a variety of stores across five cities in the United States during the summer months of 2015. Samples were evaluated for the presence of both Campylobacter and Salmonella after pre-enrichment using a commercial, closed-platform, real-time PCR (BAX) system. Potential positives were plated onto selective media according to organism and confirmed using latex agglutination. Positive Campylobacter samples were isolated and subjected to National Antimicrobial Resistance Monitoring System (NARMS) protocols to identify resistance patterns. Statistical analyses were conducted in the statistical program R to determine resistance patterns for Campylobacter and to compare prevalence of Campylobacter and Salmonella in ground beef.
Results: Among the 96 samples, 88.5% were positive for Campylobacter spp. (n=85) and 1.04% were positive for Salmonella (n=1). A total of 79 samples were successfully isolated, frozen and subjected to recovery methods with 64 isolates being successfully revitalized and subjected to NARMS protocols. MIC breakpoints determined resistance results as follows: 21.9% were resistant to ciprofloxacin (n=14), 39.1% were resistant to erythromycin (n=25), 51.6% were resistant to gentamicin (n=33), and 14.1% were resistant to tetracycline (n=9).
Significance: Retail is the final step before the product reaches the consumer, and it is important to consider pathogens that are present at retail. Determining a baseline for and Salmonella and antibiotic resistant Campylobacter in ground beef across the United States may contribute to future interventions and controls within the food processing chain.