An official website of the United States government.
Technical Objectives 1. Conduct head-to-head comparisons of newly developed antimicrobials with eight commercial antimicrobials currently being used by poultry processors through the following steps: Determine MICs and non-inhibitory concentrations (NICs) of the antimicrobials against pure cultures of L. monocytogenes and Salmonella spp in our 96 well plate, high throughput screening method. Use the "poultry skin model" we have developed to evaluate the inhibition on raw poultry and residual activities against strains of Salmonella spp. Use a "turkey deli meat" broth model to evaluate the inhibition on RTE poultry and residual activities against strains of L. monocytogenes for RTE deli turkey.<br/> 2. Standardize the production process for our antimicrobials and scale-up our laboratory prototype.<br/> 3. Using a systematic approach, we will identify the modes of action for the most effective combination of antimicrobials on the basis of their biological, physical and genetic response from Salmonella spp and L. monocytogenes. Biological/Biochemical/metabolic screen: we will determine the impact of these antimicrobials on growth curves of these two pathogens. A lengthening lag phase and smaller and shorter log phase will indicate that the antimicrobials are working. Physical screen; we will look for binding to and penetration of the Gram-negative membrane and degradation of the Gram-positive cell wall. Genetic screening of L. monocytogenes and Salmonella spp response to these test antimicrobials: we will use microarrays to determine the genetic response of these two pathogens to the commercial antimicrobials, MICs and optimal concentrations of the natural antimicrobials. This will allow us to target different sectors of the response of the pathogens including cell-to-cell signaling through blocking molecules used in quorum sensing that will minimize the pathogen's ability to develop resistance to antimicrobials.<br/> 4. We will fractionate, identify and characterize the most effective antimicrobial components present in the antimicrobials using High Performance Liquid Chromatography (HPLC), Centrifugal Partition Chromatography (CPC) and Liquid Chromatography-Mass Spectrometry (LC-MS) techniques as needed.<br/> 5. Descriptive and consumer evaluations will be used to set upper use limit for antimicrobial combinations by determining the sensory impact of the optimized antimicrobial combinations on the sensory quality in the raw and processed poultry. Separate descriptive panel analysis of the raw and cooked poultry products treated with the optimized antimicrobial combinations, consumer panels will separately test the raw, cooked and RTE poultry Modeling the sensory impacts of the antimicrobial combination in both warm (i.e. baked) and cold (i.e. RTE processed) meat products.
Non-Technical Summary:<br/>
This is a critical crossroads for the poultry industry with a majority of consumers demanding minimal or chemical free foods and the ever present threat of foodborne illness from Salmonella and Listeria associated with raw and ready-to-eat (RTE) poultry products. As a potential solution, we have demonstrated the effectiveness of novel, all natural antimicrobials. This proposed Phase II research will optimize combinations of antimicrobials that will provide additional hurdles of protection from Listeria and Salmonella to minimize the risk of foodborne illness for poultry. This research will minimize the growth of spoilage organisms to provide a much needed increase in shelf-life for these high-value products, while maintaining the quality of the organic foods. Specific details are contained in the Commercialization Plan. This proposal will add-value to agricultural wastes currently being burned as cheap fuel sources by upgrading thes waste product to food grade antimicrobials. We will do this in a sustainable manner that minimizes or eliminates most of the liquid wastes typically associated with biological extraction methods.
<P>
Approach:<br/>
1. To conduct head-to-head comparisons of newly developed antimicrobials with eight commercial antimicrobials currently being used by poultry we will: Determine MICs and non-inhibitory concentrations (NICs) of the antimicrobials against pure cultures of L. monocytogenes and Salmonella spp in our 96 well plates, high throughput screening method. Use the "poultry skin model" we have developed to evaluate the inhibition on raw poultry and residual activities against strains of Salmonella spp. Use a "turkey deli meat" broth model to evaluate the inhibition on RTE poultry and residual activities against strains of L. monocytogenes for RTE deli turkey. 3. To identify the modes of action for the most effective combination of antimicrobials on the basis of their biological, physical and genetic response from Salmonella spp and L. monocytogenes, we will use: Biological/Biochemical/metabolic screen: A lengthening lag phase and smaller and shorter log phase will indicate that the antimicrobials are working. Physical screen; look for binding to and penetration of the Gram-negative membrane and degradation of the Gram-positive cell wall. Genetic screening of L. monocytogenes and Salmonella spp response to these test antimicrobials: microarrays will be used to determine the genetic response of these two pathogens to the commercial antimicrobials, MICs and optimal concentrations of the natural antimicrobials. This will allow us to target different sectors of the response of the pathogens including cell-to-cell signaling through blocking molecules used in quorum sensing that will minimize the pathogen's ability to develop resistance to antimicrobials. 5. Sensory and consumer evaluations will be used to set upper use limit for antimicrobial combinations by determining the sensory impact using: Separate descriptive panel analysis of the raw and cooked poultry products treated with the optimized antimicrobial combinations, consumer panels will separately test the raw, cooked and RTE poultry Modeling the sensory impacts of the antimicrobial combination in both warm (i.e. baked) and cold (i.e. RTE processed) meat products.