Prevalence and Antimicrobial Resistance of Salmonella from Antibiotic-Free Broilers during Organic and Conventional Processing

Salmonella is one of the top causes for bacterial foodborne infections in the United States, emphasizing the importance of controlling this pathogen for protecting public health. Poultry and poultry products are commonly associated with Salmonella, and interventions during production and processing are necessary to manage the risk of infection due to consumption of poultry products. In recent times, the demand for organic and antibiotic-free poultry has increased owing to consumer perceptions and concerns of increasing prevalence of antimicrobial-resistant (AMR) pathogens. However, the microbiological effect of these management practices is not clear. This study was conducted to determine the difference in the AMR of Salmonella isolated from poultry processed conventionally and organically. Fecal samples, carcass rinses, and environmental samples were collected over 1 year and analyzed for the prevalence of Salmonella and AMR. Results of this experiment showed that organic chickens were associated with statistically higher levels of Salmonella during early processing steps. However, no difference in Salmonella prevalence was observed between organic and conventional carcasses postchill. In addition, for most antimicrobial agents tested, prevalence of AMR Salmonella in conventional processing was lower in this study than was reported by the National Antimicrobial Resistance Monitoring System for chickens at slaughter. These observations indicate that organic methods may introduce greater risk of Salmonella contamination; however, proper interventions during processing can abate this risk. In addition, this study supports the assertion that raising chickens without the use of antibiotics may result in lower prevalence of AMR Salmonella.