Location: Food and Feed Safety Research
2022 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
Work conducted under Objective 2 during fiscal year (FY) 2022 made significant progress, with focus on determining 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. Project work identified potential limitations in some current food processing and animal waste management practices as important contributing factors to the contamination and dissemination of pathogenic and antimicrobial resistant bacteria in animal produced foods and the production environment. Additional FY 2022 research focused on Objective 2 made significant progress in identifying, developing, and testing intervention strategies. The focus of the work is a combination 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 antibiotics. 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 while assuring microbial food safety; 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 U.S. consumer.
Accomplishments
1. Differential risks associated with Salmonella contamination of retail pork and beef during slaughter and processing. Preventing the contamination of pork and beef by Salmonella during processing remains a challenge for the food animal industry. ARS researchers at College Station, Texas, working with industry and university collaborators, examined pork and beef meat and lymph nodes from different-sourced animals during processing. Results revealed dramatic effects of season and source of animal on Salmonella prevalence, with Salmonella in pork being the highest in January and March, but being highest in cattle during the hot summer months. Conventional feedlot cattle and cull dairy cows had the highest Salmonella prevalence in both lymph nodes and feces while all-natural feedlot cattle, those not fed antibiotics or feed-additives, had the lowest prevalence. The conventional feedlot cattle and cull dairy cows had the highest frequency of multi-drug resistant Salmonella, exceeding 30%, whereas the all-natural feedlot cattle had less than 5% of their Salmonella being multi-drug resistant. The frequency of multi-drug resistant Salmonella in pork was about 20%. This work is important because it helps clarify how different production approaches, seasons, and climate regions can affect which cattle and swine are most likely to bring Salmonella to the processing facility and which animal sources may be at higher risk for antimicrobial resistant Salmonella. This accomplishment will help producers make better decisions and more effectively manage risks of microbial contamination of beef and swine products reaching the U.S. consumer.
2. Mealworm larvae, beetles, and associated microflora survive in stockpiled manure. Animal wastes, being rich in many plant-required nutrients, are often spread onto agricultural lands as a cost-effective fertilizer. However, if not properly managed this practice can unintentionally contribute to the dissemination of unwanted pathogenic and antimicrobial resistant microbes to terrestrial and watershed environments. ARS researchers at College Station, Texas, evaluated the bacterial community established within the larval and adult stages of the lesser mealworm, an insect commonly associated with animal wastes, during animal rearing, and after the wastes are removed, stored, and spread as fertilizer on nearby pastureland. The manure-associated larvae and beetles maintained a diverse and stable microbial community within their gut while on the farm, but when transferred into the environment and stockpiled onto pastureland for use as fertilizer, their microbial profile fluctuated in response to environmental influences thus disrupting the competitiveness of the insect's healthy flora. The work established that despite the challenging environmental influences associated with manure stockpiling, these beetles and their gut microflora persisted within the manure, serving as potential vectors for dissemination of unwanted pathogenic and antimicrobial resistant microbes. This accomplishment is important because it has identified specific management practices that can be improved to prevent dissemination of foodborne pathogens and antimicrobial resistant bacteria into terrestrial and watershed environments.
Review Publications
Beier, R.C., Andrews, K., Hume, M.E., Sohail, M.U., Harvey, R.B., Poole, T.L., Crippen, T.L., Anderson, R.C. 2021. Disinfectant and antimicrobial susceptibility studies of Staphylococcus aureus strains and ST398 and ST5 methicillin-resistant Staphylococcus aureus strains from swine mandibular lymph node tissue, commercial pork sausage meat and swine feces. Microorganisms. 9(11). Article 2401. https://doi.org/10.3390/microorganisms9112401.
Anderson, R.C., Levent, G., Petrujkic, B., Harvey, R.B., Hume, M.E., He, L.H., Genovese, K.J., Beier, R.C., Poole, T.L., Crippen, T.L., Nisbet, D.J. 2021. Antagonistic effects of lipids against the anti-Escherichia coli and anti-Salmonella activity of thymol and thymol-ß-D-glucopyranoside in porcine gut and fecal cultures in vitro. Frontiers in Veterinary Science. 8. Article 751266. https://doi.org/10.3389/fvets.2021.751266.
Bozic, A.K., Gutiérrez-Bañuelos, H., Corral-Luna, A., Carstens, G., Arévalos-Sánchez, M., Félix-Portillo, M., Muro-Reyes, A., Arzola-Álvarez, C., Anderson, R.C., Harvey, R.B. 2022. Dynamics of gastrointestinal activity and ruminal absorption of the methane-inhibitor, nitroethane, in cattle. Frontiers in Veterinary Science. 9. Article 817270. https://doi.org/10.3389/fvets.2022.817270.
Arsenault, R.J., Brown, T.R., Edrington, T.S., Nisbet, D.J. 2022. Kinome analysis of cattle peripheral lymph nodes to elucidate differential response to Salmonella spp. Microorganisms. 10(1). Article 120. https://doi.org/10.3390/microorganisms10010120.
Wottlin, L.R., Edrington, T.S., Anderson, R.C. 2022. Salmonella carriage in peripheral lymph nodes and feces of cattle at slaughter is affected by cattle type, region, and season. Frontiers in Animal Science. 3(1). Article 859800. https://doi.org/10.3389/fanim.2022.859800.
Wottlin, L.R., Harvey, R.B., Norman, K.N., Burciaga, S., Loneragan, G.H., Droleskey, R.E., Anderson, R.C. 2022. Prevalence and antimicrobial resistance of nontyphoidal Salmonella enterica from head meat and trim for ground product at pork processing facilities. Journal of Food Protection. 85(7):1008-1016. https://doi.org/10.4315/JFP-22-049.
Arzola-Alvarez, C., Anderson, R.C., Hume, M.E., Ledezma, E., Ruiz-Barrera, O., Castillo-Castillo, Y., Arzola-Rubio, A., Ontiveros, M., Min, B., Wottlin, L.R., Copado, R., Salinas-Chavira, J. 2022. Effect of select tannin sources on pathogen control and microbial nitrogen metabolism in composted poultry litter intended for use as a ruminant crude protein feedstuff. Frontiers in Veterinary Science. 9. Article 930980. https://doi.org/10.3389/fvets.2022.930980.
Osman, K.Y., Caldwell, T.R., Nisbet, D.J., Anderson, R.C. 2022. Innovative treatments enhancing the functionality of gut microbiota to improve quality and microbiological safety of foods of animal origin. Annual Review of Food Science & Technology. 13:433-461. https://doi.org/10.1146/annurev-food-100121-050244.
Ontiveros-Magadan, M., Anderson, R.C., Ruiz-Barrera, O., Arzola-Alvarez, C., Salinas-Chavira, J., Hume, M.E., Scholljegerdes, E.J., Harvey, R.B., Nisbet, D.J., Castillo-Castillo, Y. 2022. Evaluation of antimicrobial compounds to inhibit growth of select gram-positive pathogenic or antimicrobial resistant bacteria in air-exposed silage. Canadian Journal of Animal Science. 102:75-84. https://doi.org/10.1139/cjas-2021-0061.
