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Submitted to: Microbiology Spectrum
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/3/2015 Publication Date: 6/19/2016 Citation: Berry, E.D., Wells, J. 2016. Reducing foodborne pathogen persistence and transmission in animal production environments: Challenges and Opportunities. Microbiology Spectrum. 4(4):1-18. doi:10.1128/microbiolspec.PFS-0006-2014. Interpretive Summary: Strategies to reduce human pathogens in food animals before harvest are an important part of the farm-to-table food safety approach. The problem is complex; there are many different pathogens of concern, many animal species that are under different production and management systems, and a variety of sources of pathogens, including other livestock and domestic animals, wild animals and birds, insects, water, and feed. Preharvest food safety research has identified a number of potential intervention strategies to reduce pathogens in animals. In addition, various factors have been identified that can impact the occurrence of pathogens on the farm. While progress has been made, foodborne illnesses continue to occur. In this review, we summarize both the challenges and opportunities for reducing pathogens in food animals. Animals that excrete high levels of pathogens in their feces and pathogen strains that can persist in animals or their environment for long time periods both appear to play important roles in maintaining pathogens on the farm. Continued research and advancements in gene sequencing and other technologies are expected to reveal what causes animals to shed high levels of pathogens, and what causes pathogens to persist. This research is also expected to improve the prospects for selecting food animals that are more resistant to pathogens and improve our understanding of the factors that affect pathogen colonization of the gastrointestinal tract. It is likely that this continued research will reveal other challenges, which may suggest potential targets or control points to apply interventions for pathogen reduction in livestock. Additional benefits of the reduction of pathogens in food animals are the reduction of contamination of produce, water, and the environment, and thereby lower risk for human illnesses associated with these sources. Technical Abstract: Preharvest strategies to reduce zoonotic pathogens in food animals are important components of the farm-to-table food safety continuum. The problem is complex; there are multiple pathogens of concern, multiple animal species under different production and management systems, and a variety of sources of pathogens, including other livestock and domestic animals, wild animals and birds, insects, water, and feed. Preharvest food safety research has identified a number of intervention strategies, including probiotics, direct-fed microbials, competitive exclusion cultures, vaccines, and bacteriophage, in addition to various factors that can impact pathogens on-farm, such as seasonality, production systems, diet, and dietary additives. Moreover, this work has revealed both challenges and opportunities for reducing pathogens in food animals. Animals that shed high levels of pathogens and predominant pathogen strains that exhibit long-term persistence appear to play significant roles in maintaining the prevalence of pathogens in animals and their production environment. Continued investigation and advancements in sequencing and other technologies are expected to reveal the mechanisms that result in super-shedding and persistence, in addition to increasing the prospects for selection of pathogen-resistant food animals and understanding of the microbial ecology of the gastrointestinal tract with regard to zoonotic pathogen colonization. It is likely that this continued research will reveal other challenges, which may further indicate potential targets or critical control points for pathogen reduction in livestock. Additional benefits of the preharvest reduction of pathogens in food animals are the reduction of produce, water, and environmental contamination, and thereby lower risk for human illnesses linked to these sources. |
