Location: Food and Feed Safety Research
2023 Annual Report
Objectives
Objective 1: Determine factors affecting colonization, maintenance, and dissemination of foodborne pathogens and antimicrobial resistant bacteria in the bovine and swine gastrointestinal tract, lymphatic system and their production and processing environments.
Sub-objective 1.A: Identify and characterize factors affecting the infection, colonization, carriage and dissemination of foodborne pathogens and antimicrobial resistant bacteria within the production environment and the resident and transient populations of arthropods in farm and processing environments.
Sub-objective 1.B: Identify and characterize factors affecting colonization and maintenance of Salmonella in the swine proximal alimentary, distal gastrointestinal tract, and associated lymphatics system.
Sub-objective 1.C: Evaluate factors influencing intestinal mucosal integrity of the distal intestinal tract of feedlot cattle and correlation to Salmonella carriage in peripheral lymph nodes.
Objective 2: Identify, develop, and test interventions, including possible synergies of multiple interventions and GRAS (generally regarded as safe) alternatives, to yield effective technologies to control foodborne pathogens or mitigate their virulence and resistance.
Sub-objective 2.A: Determine best-user practices to achieve effective pathogen control for commercially relevant organic acid mixtures and biocides under the varied applications protocols currently used by industry.
Sub-objective 2.B: Overcome the lipophilic limitations of essential oils by chitosan-encapsulation, use of natural or synthetic higher molecular weight carbohydrate-glycosidic conjugates or co-administration with appropriate emulsifiers.
Sub-objective 2.C: Characterize effects of short chain nitrocompounds on hydrogen ecology, redox homeostasis, pathogen competitiveness and gene expression by zoonotic pathogens and resolve uncertainties pertaining to their safe use in animal agriculture.
Approach
The long-term goal of our project is to develop practical, cost-effective, and environmentally compatible strategies to reduce the prevalence and concentration of foodborne pathogens associated with food-producing animals, thus reducing the risk of transmission of foodborne disease and antimicrobial resistance to the American consumer. To accomplish these goals, we need to better understand ecological and biological factors affecting the ability of foodborne pathogens to colonize particular habitats present in animal agriculture and how we can interrupt their ability to survive and persist in these environments. The overall goals of Objective 1 of this project are to determine factors affecting colonization, maintenance, and dissemination of foodborne pathogens and antimicrobial resistant bacteria in the bovine and swine gastrointestinal tract, lymphatic system, and their production and processing environments. The goals of Objective 2 seek to identify, develop, and test interventions, including possible synergies of multiple interventions and GRAS (generally regarded as safe) alternatives, to yield effective technologies to control foodborne pathogens or mitigate their virulence and resistance and apply this knowledge, as well as existing knowledge, to develop interventions to reduce the colonization, carriage, and ultimately the shedding of pathogenic and antimicrobial resistant bacteria in food-producing animals. Ultimately, results obtained from this research will facilitate the development of sound, science-based microflora management strategies to improve gut health and function by reducing the risk of transmission of foodborne disease and antimicrobial resistance in food-producing animals and their production environment.
Progress Report
Significant progress was made by this project in FY 2023. Objective 1 research to determine factors affecting colonization, maintenance, and dissemination of foodborne pathogens and antimicrobial resistant bacteria in the bovine and porcine gastrointestinal tract, lymphatic system, and in production environments progressed well and data are being analyzed. Project work identified potential limitations in some current food processing and animal waste management practices, as well as prospective monitoring technologies as important contributing factors to the contamination and dissemination of pathogenic and antimicrobial resistant bacteria in animal produced foods and the production environment. Research focused on Objective 2 made significant progress in identifying, developing, and testing intervention strategies. The focus of the work is on combinations of approaches that will be additive or possibly synergistic and includes the study of interventions involving natural or GRAS (generally recognized as safe) alternatives to conventional antibiotic or pathogen control technologies. The goal is to develop effective technologies and protocols to control foodborne pathogens or mitigate their virulence and resistance. These interventions are being designed to contribute to the efficiency and profitability of animal production; industry partners are collaborating to facilitate implementation of these technologies into commercial production environments. Success in this work will help U.S. farmers and ranchers produce safer and more wholesome meat and dairy products for the consumer.
Accomplishments
1. Pathogen carriage by flies does not correlate to pathogen burden on dairy farms. Dairies are critical components of the U.S. and worldwide food production system. As dairies continue to become larger and more intensified, there becomes an increasing environmental burden on the farm ecosystem. To better understand microbial food safety risks associated with large dairies, ARS researchers at College Station, Texas, evaluated the microbial communities associated with dairy farms. The work focused on manure, lagoons, feed/water troughs, and associated interactions with two different fly species, house flies (sponge feeding) and stable flies (blood feeding). Results revealed that significant differences exist between microbial populations across nearly all of the microenvironments within the dairy. The two fly species harbored foodborne pathogen populations similar to each other but not with the other microenvironments sampled. This accomplishment is important because it will help guide dairy farmers in properly evaluating emerging technologies that use pathogen levels in flies as sentinels of the environmental health of the dairy. Science-based technologies, as evidenced by this accomplishment, will be critical to the ongoing commitment of the dairy industry to produce safe and wholesome foods for the consumer.
2. Reclamation of silages contaminated by pathogens and antimicrobial resistant bacteria. Aerobic exposure of silages due to inappropriate processing or during feed-out promotes growth of spoilage, and of pathogenic and drug resistant microbes which can risk infection of food-producing animals and the foodstuffs they produce. Livestock producers are committed to finding effective, environmentally friendly ways to safely utilize these spoiled feedstuffs while preserving their nutritional value. ARS researchers at College Station, Texas, working with industry and academic collaborators, developed new mitigation strategies to reduce foodborne pathogens and antimicrobial resistant bacteria in spoiled silages and feedstuffs. Mixtures of naturally occurring plant products, including dimethyl sulfone, hops, and certain medium chain fatty acids, rescued aerobically spoiled silages by preventing the proliferation of molds, butyrate-producing bacteria, and even foodborne pathogens and antimicrobial resistant bacteria. This accomplishment, when refined and adapted to commercial dairy scale, will enhance dairy efficiency and profitability while meeting the ongoing commitment to produce safe and wholesome dairy products in an environmentally sensitive and sustainable manner.
Review Publications
Latham, E.A., Anderson, R.C., Wottlin, L.R., Poole, T.L., Crippen, T.L., Schlosser, W.D., Harvey, R.B., Hume, M.E. 2022. Inhibitory effect of select nitrocompounds and chlorate against Yersinia ruckeri and Yersinia aleksiciae in vitro. Pathogens. 11. Article 1381. https://doi.org/10.3390/pathogens11111381.
Zúñiga-Serrano, A., Barrios-García, H.B., Anderson, R.C., Hume, M.E., Ruiz Albarrán, M., Bautista Martínez, Y., Sánchez-Guerra, N.A., Vázquez-Villanueva, J., Infante Rodríguez, F., Salinas-Chavira, J. 2022. Antimicrobial and digestive effects of Yucca schidigera extracts related to production and environment implications of ruminant and nonruminant animals: A review. Agriculture. 12(8). Article 1198. https://doi.org/10.3390/agriculture12081198.
Poole, T.L., Schlosser, W.D., Crippen, T.L., Swiger, S.L., Norman, K.N., Anderson, R.C. 2023. Whole-genome sequence of Aeromonas spp. isolated from a dairy farm in central Texas. Microbiology Research. 14:161-176. https://doi.org/10.3390/microbiolres14010014.
Castillo-Castillo, Y., Arzola-Alvarez, C., Fonseca, M., Salinas-Chavira, J., Ontiveros-Magadan, M., Hume, M.E., Anderson, R.C., Flythe, M.D., Byrd II, J.A., Ruiz-Barrera, O. 2023. Effects of hops treatment on nitrogen retention, volatile fatty acid accumulations, and select microbial populations of composting poultry litter intended for use as a ruminant feedstuff. Microorganisms. 11(4). Article 839. https://doi.org/10.3390/microorganisms11040839.
Arzola-Alvarez, C., Ruiz-Barrera, O., Castillo-Castillo, Y., Ontiveros, M., Fonseca, M., Jones, B.W., Smith, W.B., Hume, M.E., Harvey, R.B., Poole, T.L., Anderson, R.C., Arzola-Lira, A., Salinas-Chavira, J. 2023. Effects in air-exposed corn silage of medium chain fatty acids on select spoilage microbes, zoonotic pathogens, and in vitro rumen fermentation. Journal of Environmental Science and Health. 58:45-50. https://doi.org/10.1080/03601234.2023.2168449.
Tsai, G.E., Anderson, R.C., Kotzur, J.M., Davila, E., Mcquitty, J., Nelson, E. 2022. Bay salt in seventeenth-century meat preservation: how ethnomicrobiology and experimental archaeology help us understand historical tastes. British Journal of Historical Science-Themes. 7:63-93. https://doi.org/10.1017/bjt.2022.7.
Ochoa-Garcia, P.A., Anderson, R.C., Arevalos-Sanchez, M.M., Rodriguez-Almeida, F.A., Felix-Portillo, M., Muro-Reyes, A., Bozic, A., Arzola-Alvarez, C., Corral-Luna, A. 2021. Astragalus mollissimus plant extract: a strategy to reduce ruminal methanogenesis. Tropical Animal Health and Production. 53. Article 436. https://doi.org/10.1007/s11250-021-02882-1.
