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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Foodborne Toxin Detection and Prevention Research » Research » Research Project #430817

Research Project: Biocontrol Interventions for High-Value Agricultural Commodities

Location: Foodborne Toxin Detection and Prevention Research

2018 Annual Report

4. Accomplishments
1. Mass rearing of navel orangeworm. Mass rearing (i.e. millions of moths per day) is one of the critical elements of an efficient sterile insect technology (SIT) program. The current SIT program operated by Animal and Plant Health Inspection Service (APHIS) in Phoenix, Arizona, utilizes glass jars under simulated daylight for mass rearing. ARS scientists in Albany, California, developed a new rearing system in which the larvae develop without light, resulting in faster insect development and substantially higher egg count. Results indicate that this method significantly increases moth production with minimal added effort or cost.

2. Isolation and characterization of biocontrol agents to reduce the growth of Salmonella on produce. ARS Scientists in Albany, California, created a library of bacteria normally associated with produce. This library was screened to identify bacteria capable of inhibiting the growth of Salmonella. Two isolates inhibited the growth of Salmonella on cantaloupe melons. The genomes of these bacteria were sequenced, and have revealed clues as to the mechanisms of Salmonella growth inhibition. Patents have been filed for these organisms, which could be used as biocontrol agents for farmers interested in inhibiting growth of bacterial pathogens in produce and farm environments.

3. Identification of an atoxigenic strain of Aspergillus flavus for use in the biocontrol of toxigenic fungal species. Aflatoxins, which can be present in nuts, are widely recognized as a major health problem. ARS scientists in Albany, California, identified an effective biocontrol agent that inhibited aflatoxin production by toxigenic Aspergillus flavus. The DNA and RNA of this strain was extracted, sequenced and assembled into two databases for gene discovery and expression studies. The libraries are useful to elucidate the genetic bases of effective biocontrol agents and for the identification of the relevant metabolic capabilities of atoxigenic A. flavus strains that promote biocontrol-related management of toxin contamination. These studies help define the most effective mycotoxin biocontrol agents for nut and farm crops.

4. Identification of natural cinnamic derivatives that interfere with fungal cell wall system. Due to increasing concerns about the safety of certain antifungal drugs that have been in wide use, and the impact of repeated exposure to these compounds on health and fungal resistance, there are constant demands for new antifungals or drug potentiators with improved health and safety profiles. To that end, ARS researchers in Albany, California, identified natural cinnamic derivatives that prevent fungal growth by disrupting the cell wall integrity of pathogens. The efficacy of caspofungin or octyl gallate, commercial cell wall disrupting agents, can be augmented by the co-application of cinnamic acid-1 (CA-1). Cinnamic derivatives can also overcome fludioxonil (fungicide) tolerance of Aspergillus antioxidant mutants. Collectively, natural cinnamic derivatives can be used to enhance current anti-pathogenic fungi treatments, allowing the reduced use of toxic antifungal agents or fungicides, thus leading to better human health and environmental impacts.

Review Publications
Kim, J., Chan, K.L., Cheng, L.W. 2017. Cinnamic acid analogs as intervention catalysts for overcoming antifungal tolerance. Molecules. 22(10):1783.

Hua, S.T., Palumbo, J.D., Parfitt, D., Sarreal, S.L., O'Keeffe, T.L. 2018. Development of a droplet digital PCR assay for population analysis of aflatoxigenic and atoxigenic Aspergillus flavus mixtures in soil. Mycotoxin Research. 34(3):187-194.

Babrak, L.M., McGarvey, J.A., Stanker, L.H., Hnasko, R.M. 2017. Identification and verification of hybridoma-derived monoclonal antibody variable region sequences using recombinant DNA technology and mass spectrometry. Molecular Immunology. 90:287-294.

Hnasko, R.M., Lin, A.V., McGarvey, J.A., Stanker, L.H. 2018. Enhanced detection of infectious prions by direct ELISA from the brains of asymptomatic animals using DRM2-118 monoclonal antibody and Gdn-HCl. Journal of Immunological Methods. 456:38-43.

Hnasko, R.M., Lin, A.V., Stanker, L.H., McGarvey, J.A. 2018. A bioassay for the optimization of macrophage conditioned medium (MCM) as culture supplement used to promote hybridoma cell survival and growth. Monoclonal Antibodies in Immunodiagnosis and Immunotherapy. 37(3):126-133.

Hua, S.T., Parfitt, D.E., Sarreal, S.L., Lee, B.G., Wood, D.F. 2018. First report of an atypical new Aspergillus parasiticus isolates with nucleotide insertion in aflR gene resembling to A. sojae. Mycotoxin Research. 34(2):151-157.

Kim, J.H., Chan, K.L., Cheng, L.W. 2018. Octyl gallate as an intervention catalyst to augment antifungal efficacy of caspofungin. Open Access Journal of Multidisciplinary Science. 1(1):19-28.

Liang, P., Haff, R.P., Hua, S.T., Munyaneza, J.E., Yilmaz, M.T., Sarreal, S.L. 2017. Nondestructive detection of zebra chip disease in potatoes using near-infrared spectroscopy. Biosystems Engineering. 166:161-169.

Singh, A., Nisha, Bains, T., Hahn, H.J., Liu, N., Tam, C.C., Cheng, L.W., Kim, J.H., Debnath, A., Land, K.M., Kumar, V. 2017. Design, synthesis and preliminary antimicrobial evaluation of n-alkyl chain tethered c-5 functionalized bis-isatins. MedChemComm. 8(10):1982-1992.

Tran, T., Huynh, S., Parker, C., Hnasko, R.M., Gorski, L.A., McGarvey, J.A. 2018. Complete genome sequences of three Bacillus amyloliquefaciens strains that inhibit the growth of Listeria monocytogenes in vitro. Genome Announcements. 6(25):e00579-18.

Yin, G., Hua, S.T., Pennerman, K.K., Yu, J., Bu, L., Sayre, R.T., Bennett, J. 2018. Genome sequence and comparative analyses of atoxigenic Aspergillus flavus WRRL 1519. Mycologia. 110(3):482-493.