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United States Department of Agriculture

Agricultural Research Service

PMR News

Focus on Fungal Infections 18 logo

  • Overcoming antifungal drug resistance by using natural compounds. PMR scientists have shown that natural compounds can act as chemosensitizers for drug-resistant strains of pathogenic fungi. The findings were presented at Focus on Fungal Infections 18, an international conference on treatment of human pathogenic fungal diseases, in San Antonio, TX, Mar 5-7, 2008. The poster, "Overcoming antifungal drug resistance using chemosensitization: Targeting stress response pathways of fungi with benzo analogs", won the Thomas J. Walsh Clinical Mycology Award for the most innovative and outstanding achievement in the field of research on infectious fungal diseases at the conference. (Poster is available in PDF format here.) This marks the first time that non-medical researchers were recognized. Initially, PMR scientists developed the chemosensitization concept for agricultural fungal pathogens (see next item). The gene targets (stress response pathways) were determined by using fungal mutants provided by Gregory S. May, Division of Pathology and Laboratory Medicine, MD Anderson Cancer Center, University of Texas, Houston. Several natural compounds were tested against drug-resistant strains of clinical fungal pathogens, in combination with commercial antifungal drugs. This work was done in collaboration with Natalia C. G. Faria, at the Institute of Hygiene and Tropical Medicine, New University of Lisbon, Portugal. The co-application of natural compounds with antifungal drugs significantly reduced the dosages needed to inhibit growth of the clinical strains. Lower effective dosages should lower costs and potential negative side effects, and may also reduce the potential for development of resistance in the fungi to new antifungal agents. The results on chemosensitization of Aspergillus fumigatus have been published in Biochemical and Biophysical Research Communications 372: 266-271, 18 July 2008. This paper was also highlighted in the July 2008 issue of the Aspergillus Newsletter in the Latest News and Articles section here.

    PMR is seeking potential research collaborators and commercial partners (agricultural or medical) on use of chemosensitization to improve efficacy of antifungal agents. Please contact our technology transfer office for details.

  • Natural chemicals found that enhance antifungal activity of commercial fungicides. PMR scientists have discovered a number of natural phenolic compounds that improve the antifungal activity of commercial fungicides. These phenolics act as chemosensitizing agents that disrupt the fungal cell in response to stress. Such chemosensitizing enhancement has been found to be effective against pre- and post-harvest fungal pathogens of fruits, such as apples and oranges. Reprint is available: FEMS Microbiology Letters 281: 64-72.

    Invention Report filed and accepted Feb 2008

  • Antioxidants control genes that suppress aflatoxin biosynthesis. PMR scientists, in collaboration with ARS scientists from New Orleans and the J. Craig Venter Institute, have found a group of genes, peroxiredoxins, that can shut down aflatoxin biosynthesis. Previously, PMR scientists discovered that certain natural antioxidants, such as gallic acid, could prevent aflatoxin biosynthesis ( Mahoney and Molyneux 2004). Using a recently available genetic tool called microarray analysis, the collaborating team of scientists were able to show that antioxidants turned on this group of genes. Peroxiredoxins remove signals that trigger aflatoxin biosynthesis. This discovery allows development of strategies to regulate these genes so that aflatoxin is not produced when the fungus infects certain agricultural products, such as peanuts, corn, cotton and tree nuts. Reprint is available: Int'l J. Food Microbiology 122: 49-60.

  • Eutypa-infected grapevine
    Eutypa dieback symptoms on grapevine include stunted shoots and leaf development. See right side of foliage.

  • Pathogenesis of Eutypa in grapevine. PMR scientists, in collaboration with scientists at the University of California, Davis, recently received the "Editor's Pick"in the journal Phytopathology. The Editor-in-Chief, Dr. Robert Gilbertson, selected their paper ( Phytopathology 98: 222-229, 2008) noting that "new insight into the mechanism by which the vascular pathogen, Eutypa lata, infects and causes disease is revealed by examining the grapevine wood polymers degraded and enzymes and secondary metabolites produced by the fungus. The results revealed a possible mechanism of disease tolerance in grapevine, and raised important new questions about fungal colonization of woody hosts."

    Related PMR Eutypa publications: 2003, 2004, 2005, 2006a, 2006b

  • infested wheat kernel x-ray image and one dimensional signal
    Wheat kernel image (left);
    1D signal (right)

  • One dimensional x-ray inspection. PMR engineers have designed a simplified version of a linescan x-ray unit with the goal of performing food inspection tasks without the hassle and expense of a full scale machine.With this new technology, a one dimensional signal replaces the traditional two dimensional image. For certain inspection tasks this arrangement has been shown to be equal or superior to traditional imaging in terms of the ability to detect defects or contaminants. This new technology is being applied to a number of inspection tasks, including the detection of pits in cherries and insect infestation in wheat.

  • Large-scale volatile organic compound collection system
    Large-scale VOC collection

  • In situ volatile organic compound collections. In collaboration with Paramount Farming Company and the Almond Board of California, PMR researchers have designed and implemented small-scale and large-scale volatile organic compound (VOC) collection systems. These systems are capable of monitoring VOC emissions directly from almonds (or other analytes) intact on the tree (in situ analysis). The small-scale collection system utilizes solid-phase microextraction (SPME) to adsorb the VOCs, while the large-scale system utilizes Tenax as the absorbent medium. Both systems incorporate customized, inert collection bags designed by PMR scientists. VOCs collected via these systems can be analyzed via a gas chromatogram coupled to a mass spectrometer (GC-MS), and/or used in bioassays with an electroantennogram detector (EAG) and the navel orangeworm moth.

    Related PMR VOC collection publications: 2007, 2008, 2009, 2011

    EAG video: 2012

  • Flight tunnel for moth bioassays
    Flight tunnel bioassay

    Specific behavioral bioassays are being used to determine both adult moth (arousal, orientation to traps in cages, and flight tunnel) and larval worm (orientation arenas and servo-sphere) sensitivity and attraction to candidate VOCs. Identified attractants will be developed into lure formulations for monitoring and "attract and kill" control tactics against both adults and larvae.



    An ARS Research Associate proposal stemming from PMR's VOC research, "Method Development to Identify Natural Chemical Lures for Control of Navel Orangeworm and Light Brown Apple Moth," has been selected for headquarters' funding.

    flask with almond hull extract

  • Industrially important hydrocarbon captured as a volatile from an almond hull fungus. While investigating the volatile emission of almond hulls and fungi from almond hulls, PMR scientists have discovered a fungus that produces relatively large quantities of styrene - an industrially important chemical used in many plastics. This strain of Fusarium oxysporum could be used as a potential green source of a vital commercial chemical. The discovery, and methods to perform large-scale production and isolation, have been published in the Journal of Agricultural and Food Chemistry 56(23):11392-11398. Abstract is available here.

  • Navel orangeworm larva
    Navel orangeworm larva among Aspergillus spores

  • Navel orangeworm activity can promote aflatoxin contamination of almonds. A major insect pest of almonds, the navel orangeworm, has been found by PMR scientists to be a major contributor to promoting infection of almonds by the fungus that produces aflatoxin. This insect can carry the spores of this fungus (Aspergillus) to the almond kernel. The spores can then infect the almond through feeding wounds produced by the insect. Funding for this pilot study was provided by the Almond Board of California. The research was presented at the 2008 APS Centennial Meeting in Minneapolis. Abstract is available here.

  • A research collaboration involving Dr. Bruce Campbell, Research Leader, and two Russian scientists, Dr. Vitaly Dzhavakhiya (Russian Research Institute of Phytopathology, VNIIF) and Dr. Radii Khomutov (Russian Academy of Sciences, Moscow) has been funded by the ARS Office of International Research Programs (OIRP). The project is established under OIRP's Former Soviet Union Scientific Cooperation Program. The research will focus on novel approaches to reduce fungal infection and mycotoxin biosynthesis by using new, safe methods that target polyketide synthase and antioxidative stress-response systems of fungi. You may read more about this collaboration in this ARS News release: "New Pairs of Compounds May Help Tree Nuts Fight Fungal Foe." 

  • Press
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    Agricultural Research- USDA's science magazine, published monthly by the ARS Information Staff ( magazine homepage):

    Also see footer for additional ARS Information Staff articles featuring PMR's research.

      Meetings (2007-11)


      Here are some of the meetings PMR scientists have participated in during 2007-2011 :

      2011

      Mar 15-20, 2011 26th Fungal Genetics Conference
      Asilomar, CA
      info
      Mar 27-31, 2011 241st ACS National Meeting
      Anaheim, CA
      info
      Nov 13-16, 2011 Entomological Society of America 59th Annual Meeting
      Reno, NV
      info

      2009

      Jan 21-23, 2009 41st Annual Walnut Research Conference
      Bodega Bay, CA
      info
      Feb 17-20, 2009 ARS/FSIS Annual Food Safety Workshop
      Shepherdstown, WV
      Mar 15-17, 2009 6th International Aspergillus Meeting
      Asilomar, CA
      info
      Mar 17-22, 2009 25th Fungal Genetics Conference
      Asilomar, CA
      info
      Mar 22-26, 2009 237th ACS National Meeting
      Salt Lake City, UT
      info
      abstract
      Mar 29- Apr 2, 2009 Pacific Branch Entomological Society of America 93rd Annual Meeting
      San Diego, CA
      info
      May 17- 21, 2009 American Society for Microbiology 109th General Meeting
      Philadelphia, PA
      info
      abstract
      Jun 21-24, 2009 ASABE 2009: American Society of Agricultural and Biological Engineers Annual International Meeting
      Reno, NV
      info
      abstract1
      abstract2
      Jun 21-26, 2009 Gordon Research Conference on Mycotoxins and Phycotoxins
      New London, NH
      info
      Jun 27-Jul 1, 2009 50th Anniversary Meeting of the American Society of Pharmacognosy
      Honolulu, HI
      info
      Aug 1-5, 2009 2009 American Phytopathology Society Annual Meeting
      Portland, OR
      info
      Aug 9-14, 2009 Gordon Research Conference on Floral and Vegetative Volatiles
      Oxford, UK
      info
      Sep 9-11, 2009 International Society for Mycotoxicology Conference 2009
      Vienna, Austria
      info
      Sep 13-16, 2009 123rd AOAC International Annual Meeting
      Philadelphia, PA
      info
      Dec 9-10, 2009 37th Annual Almond Industry Conference
      Modesto, CA
      info

      2008

      Jan 16-19, 2008 3rd Advances Against Aspergillosis
      Miami, FL
      info
      Feb 21-23, 2008 American Council for Food Safety 100th Anniversary
      Monterey, CA
      info
      Feb 25-26, 2008 US Pistachio Industry 2008 Conference
      Santa Barbara, A
      info
      Mar 5-7, 2008 Focus on Fungal Infections 18
      San Antonio, TX
       
      Apr 6-10, 2008 Spring 2008 National ACS Meeting
      New Orleans, LA
      info
      Nov 17-18, 2008 World Mycotoxin Forum - 5th Conference
      Noordwijk, The Netherlands
      info
      Dec 10-11, 2008 The 36th Almond Industry Conference
      Modesto, CA
      info
      abstract

      2007

      Mar 18-20, 2007 4th International Aspergillus Meeting
      Pacific Grove, CA
      info
      Mar 20-25, 2007 24th Fungal Genetics Conference
      Pacific Grove, CA
      info
      Jun 17-20, 2007 ASABE Annual International Meeting
      Minneapolis, MN
      info
      Jun 17-21, 2007 Gordon Research Conference on Mycotoxins and Phycotoxins
      Waterville, ME
      info
      Jul 14-18, 2007 48th Annual Meeting of the American Society of Pharmacognosy
      Portland, ME

      abstract1
      abstract2
      Jul 28-Aug 1, 2007 2007 American Phytopathological Society-Society of Nematologists Joint Meeting
      San Diego, CA
      info
      Oct 22-24, 2007 2007 Multi Crop Aflatoxin/Fumonisin Elimination Workshop and Fungal Genomics Workshop
      Atlanta, GA
      proceedings


      Meetings (2005-6)


      Here are some of the meetings PMR scientists have participated in during 2005 and 2006:

      2006

      Jan 11-13, 2006 80th Annual Western Orchard Pest & Disease Management Conference: abstract1; abstract2 Portland, OR info
      Feb 22-25, 2006 2nd Advances Against Aspergillosis Conference Athens, Greece info
      Feb 27, 2006 Multicrop Aflatoxin Technical Working Group Albany, CA info
      Mar 5-8, 2006 2006 Pacific Branch Entomological Society of America 90th Annual Meeting Wailea, HI info
      Apr 8-11, 2006 8th European Conference on Fungal Genetics Vienna, Austria
      Jun 25-29, 2006 16th Congress of the International Society for Human and Animal Mycology Paris, France
      Jul 4-8, 2006 2nd FEMS Congress of European Microbiologists Madrid, Spain
      Jul 9-12, 2006 ASABE 2006 Annual International Meeting: abstract Portland, OR info
      Jul 23-28, 2006 25th IUPAC International Conference on Biodiversity and Natural Products Kyoto, Japan info
      Jul 25-27, 2006 California Conference on Biological Control V: abstract Riverside, CA info
      Jul 29-Aug 2, 2006 2006 American Phytopathological Society Annual Meeting Quebec City, Quebec info
      Aug 5-9, 2006 47th Annual Meeting of the American Society of Pharmacognosy Arlington, VA
      Sep 4-6, 2006 IOBC Workshop on Arthropod Pest Problems in Pome Fruit Production Lleida, Spain info
      Sep 10-14, 2006 American Chemical Society
      232nd National Meeting
      San Francisco, CA info
      Sep 11-15, 2006 5th International Workshop on Grapevine Trunk Disease Davis, CA info
      Sep 26-30, 2006 Mycoglobe International Conference 2006 Monopoli, Italy info
      Oct 16-18, 2006 2006 Annual Multicrop Aflatoxin/Fumonisin Elimination and Fungal Genomics Workshop
      Contact Paul Williams, Corn Host Plant Resistance Research Unit for details
      Ft. Worth, TX proceedings

      2005

      Jan 20-21, 2005 4th International Workshop on Grapevine Trunk Diseases Stellenbosch, South Africa info
      Jan 23-26, 2005 43rd Annual Congress: Southern African Society for Plant Pathology Hartenbos, South Africa info
      Jan 26-28, 2005 37th Annual Walnut Research Conference Bodega Bay, CA info
      Mar 13-15, 2005 2nd Aspergillus Meeting (Aspergillus Genomics Research Policy Committee) Pacific Grove, CA (Asilomar) info
      Mar 15-20, 2005 23rd Fungal Genetics Conference Pacific Grove, CA (Asilomar) info
      Apr 18-22, 2005 1st International Conference on Plant-Microbe Interactions: Endophytes and Biocontrol Agents Saariselkä, Finland
      Jun 6-10, 2005 7th International Symposium on Poisonous Plants Logan, UT info
      Jun 19-24, 2005 Gordon Research Conference on Mycotoxins and Phycotoxins Waterville, ME info
      Jul 5-7, 2005 EU-USA Bilateral Workshop on Biodiversity, Genomics, and Advanced Methods for Detection of Mycotoxins and Toxigenic Fungi:  abstract New Orleans, LA info
      Jul 10-15, 2005 Gordon Research Conference on Plant Metabolic Engineering Tilton, NH info
      Jul 30-Aug 3, 2005 2005 American Phytopathological Society Annual Meeting Austin, TX info
      Oct 23-26, 2005 2005 Multi-Crop Aflatoxin/Fumonisin Elimination and Fungal Genomics Workshop Raleigh, NC proceedings
      Nov 10-11, 2005 World Mycotoxin Forum-Third Conference Noordwijk, the Netherlands info
      Dec 15-20, 2005 2005 International Chemical Congress of Pacific Basin Societies (Pacifichem) Honolulu, HI


      Meetings (2004)

      Here are some of the meetings PMR scientists have participated in during 2004:

      April 17-20, 2004 7th European Conference on Fungal Genetics
      abstract
      Copenhagen, Denmark
      May 17-21, 2004 XI International IUPAC Symposium on Mycotoxins and Phycotoxins Bethesda, MD info
      May 23-27, 2004 104th General Meeting
      American Society for Microbiology
      abstract
      New Orleans, LA
      Jun 16-18, 2004 First International Congress on Antioxidant Methods Orlando, FL
      Jul 31-Aug 4, 2004 2004 Annual Meeting
      American Phytopathological Society
      Anaheim, CA info
      Aug 1-4, 2004 2004 Annual International Meeting
      American Society of Agricultural Engineers
      abstract
      Ottawa, Canada
      Sep 9-11, 2004 Advances Against Aspergillosis San Francisco, CA info
      Sep 26-30, 2004 Pheromones and Other Semiochemicals in Integrated Production IOBC Working Group Meeting Trentino, Italy info
      Oct 23-25, 2004 3rd International Conference on Natural Products Nanjing, China info
      Oct 25-28, 2004 2004 Multicrop Aflatoxin/Fumonisin Elimination and Fungal Genomics Workshop Sacramento, CA proceedings


      Awards archive

      Bruce C. Campbell, Research Leader, has been elected as a Fellow of the American Association for the Advancement of Science(Section: Agriculture, Food, and Renewable Resources).

      Russell J. Molyneux, Research Chemist, has been elected as a Fellow of the American Association for the Advancement of Science(Section: Agriculture, Food, and Renewable Resources). Dr. Molyneux was also named the recipient of the 2007 Kenneth A. Spencer Award for outstanding achievement in food and agricultural chemistry. This prestigious award is administered by the American Chemical Society, Kansas City Section. The award was presented February 16, 2007 as part of a two-day symposium. Invited speakers included James Seiber (Center Director, WRRC), Bruce Campbell, and WRRC emeritus chemists Gary Manners and Attila Pavlath. Program details here.

      Gloria B. Merrill, Chemist, is one of the recipients of the 2004 ARS Administrator's Equal Employment Opportunity and Civil Rights Award. She has been recognized as one of the founders and coordinators of the WRRC Agricultural Sciences Academic Workshop. This unique outreach program encourages minority high school students in the community to learn about careers in science through hands-on training and lectures from WRRC scientists.

      Douglas M. Light, Research Entomologist, has been awarded a 2005 ARS Superior Efforts in Technology Transfer Award (Pacific West Area) for his patented research “in the development and transfer of environmentally friendly technologies that substantially enhance monitoring and control of the codling moth on apple, pear and walnut crops, worldwide.”



      ARS News Articles

      Botulism-causing Toxins Detected Promptly by ARS-developed Test Strip
      Feb 07, 2014
      New Pairs of Compounds May Help Tree Nuts Fight Fungal Foe
      Apr 28, 2011
      Helpful Yeast Battles Food-Contaminating Aflatoxin
      Jan 27, 2010
      Foodborne Staph Toxin Pinpointed by New Assay
      Dec 14, 2009
      Botulism Assay Quickly Detects Potent Foodborne Toxin
      May 04, 2009
      Olive Fruit Fly Damage Pinpointed by X-ray Vision
      Feb 26, 2009
      Invention Detects Hidden Dried Plum Pits
      Dec 01, 2006
      Tasty Nuts' Natural Defense: Caffeic Acid?
      Oct 10, 2006
      Walnuts' Secret Defense Explored
      Mar 09, 2005
      New Lure for Codling Moths
      Jun 20, 2001
      Last Modified: 8/6/2013