ARS USDA
Successful execution of these Objectives will contribute to field by: improving our knowledge of how microbial populations can affect and impact food safety and public health and delineating how pathogens are transmitted and disseminated in and among plant crops allowing for future development of improved/alternate interventions and control strategies
(Objectives 1-4); developing novel intervention strategies using sustainable, natural fungicide alternatives that eliminate aflatoxigenic fungi; enhancing our knowledge regarding the prevalence of azole-resistant aspergilli with enhanced aflatoxin production
(Objective 5); and developing novel methods to control invasive insect pests and reducing the need for the use of radioisotopes for irradiation
(Objective 6). These Objectives, if successful, will allow growers to produce a safer food supply and reduce the use of toxic chemicals (pesticides) and enhance environmental quality.
Objective 1: Identify and characterize agricultural soils that suppress the persistence of the human pathogenic bacteria Salmonella enterica, Listeria monocytogenes and Escherichia coli O157:H7.
Objective 2: Examine the microbiomes, potential for human pathogen colonization, and effectiveness of biological control agents on lettuces grown in indoor vertical hydroponic systems.
Objective 3: Examine the effects of bacterial biocontrol candidate strains on population dynamics of black Aspergillus spp. on grapes and raisins.
Objective 4: Identification and utilization of antifungal metabolites from microbial sources as interventions. •
Sub-objective 4A: Identification of antifungal metabolites from candidate biocontrol bacteria collected from raisin grape vineyards. •
Sub-objective 4B: Isolation and characterization of bacteria with antifungal activities from pistachio orchards.
Objective 5: Development of resistance management augmenting fungal and mycotoxin elimination. •
Sub-objective 5A: Determine the prevalence of azole-resistant aspergilli (A. flavus, A. parasiticus) that produce increased levels of mycotoxins in California tree nut orchards. •
Sub-objective 5B: Develop new intervention strategies for the control of azole-resistant Aspergillus species utilizing natural products/derivatives as fungicide alternatives.
Objective 6: Investigate novel methods to address mycotoxin contamination of tree nuts through control of fungal and insect vectors. •
Sub-objective 6A: Evaluate X-ray based irradiation as an alternative to gamma irradiation for SIT. •
Sub-objective 6B: Investigate high pressure steam as a tool for orchard sanitation through destruction of overwintering NOW larvae in pistachio mummies.
Objective 7: The use of previously approved natural products as an accelerated chemical interventions strategy to inhibit food-associated mycotoxins, fungal pathogens, and their insect pest transmitters. •
Sub-objective 7A: Identify previously approved natural products that inhibit mycotoxins and fungal pathogens frequently found in food contaminations. •
Sub-objective 7B: Identify previously approved natural products that immunosuppress insect pests and increase their sensitivity to microbes.