Detection, characterization, and inhibition of foodborne pathogens, toxins, and spoilage microorganisms

Major goals and specific objectives of this project:To examine the use of biological interventions (bacteriocins of lactic acid bacteria; bacteriophage) to inhibit pathogens and spoilage organisms in foods.Multiple Mode-of-Action (MOA). Comprise a 'bacteriocin cocktail' containing as many MOAs as possible (4-5?).Bac+ culture isolations and identifications using bacteriocin PCR array, Mass Spec.Bacteriocins: surface applications. Use of bacteriocin-containing fermentates as surface antimicrobials to inhibit L. monocytogenes on RTE meats as multi-MOA mixtures.Bacteriocins: added into foods. Use of MOA mixtures or with other antimicrobials.Bacteriocins: use of bacteriocin-producing LAB (Bac+ LAB) cultures. to inhibit pathogens/spoilage organisms in food (using the cultures themselves in foods).Bac+ LAB cultures to modify vegetable nitrate into nitrite for applications against Clostridium spp. in vacuum packaged foods.Generate 'commercialized bacteriocins' in a form that can be used by companies to test in their products (liquid concentrate, freeze-dried powders).2. 'Natural Nitrite'. To use 'natural nitrite' (i.e., vegetable-source nitrate → microbial fermentation conversion to nitrite) for control of Clostridia spp. in vacuum-packaged products.Identify the effectiveness of Bac+ LAB to inhibit Clostridium sporogenes (and/or Cl. perfringens). To use 'green label' culture fermentate preparations derived from GRAS LAB to inhibit and reduce survival of Cl. sporogenes, Cl. perfringens.Identify the effectiveness of Bac+ LAB to inhibit spore germination of Clostridium sporogenes (and/or Cl. perfringens). To use 'green label' culture fermentate preparations derived from GRAS LAB to inhibit spore germination from Cl. sporogenes, Cl. perfringens.Compare Bac+ LAB fermentates with 'natural nitrite ' commercial fermentates. To compare our mixed-mode-of-action culture fermentates with the effectiveness of other commercial culture fermentates for inhibition of L. monocytogenes on hotdogs.Examine Bac+ LAB for the ability to modify vegetable-nitrate into nitrite. To examine the ability of our 'green label' anti-listerial/anti-clostridial LAB to convert vegetable-sourced nitrate to nitrite while simultaneously producing the inhibitory bacteriocins in their fermentates.Examine Bac+ LAB fermentates to inhibit Clostridium sporogenes spores/cells in processed RTE and vacuum-packaged meats. To examine the effect of our mixed-MOA LAB culture fermentates on preventing germination of Clostridium spores, or inhibition of Clostridium vegetative cells, in vacuum-packaged cooked meats.3. Probiotic bacteria. Analysis of probiotic bacteria that may be beneficial to animals.Culture collection 1 (Muriana). Several hundred cultures have been isolated from retail/raw foods and from animal sources and evaluated for bacteriocin production. We will also examine a number of characteristics that might contribute to ruminant (or non-ruminant) digestion such as starch-, lipid-, and protein-hydrolysis, bile resistance, adherence to tissue culture cells as a potential indication to adherence to intestinal epithelia, and other characteristics.Culture collection 2 (Gilliland). Another culture collection is available from which were derived the largest IP revenue for Oklahoma State University (cultures licensed to Chrs. Hansen for 'BovamineTm ' microbial product for cattle.New animal isolates (FAPC slaughter). The R.M. Kerr Food & Ag Products Center routinely harvests ~160 cattle, 360 swine, 40 goats, 5 sheep annually in their slaughter facility. These present an opportunity to collect bacterial isolates from freshly harvested animals.4. Foodborne pathogens and spoilage organisms. Characterization of foodborne pathogens and spoilage organisms.Various pathogenic and spoilage bacteria have special attributes that contribute to their problematic nature with foods. Strains of L. monocytogenes that are strongly-adherent persist in food processing establishments; spoilage organisms that produce 'slime' (dextrans) or gas become problematic to meat processors. Molecular or biochemical examination of special attributes (adherence, biofilm formation, gas/slime production) of pathogens or spoilage organisms may help find solutions to alleviate problems with organisms.