Identification of swainsonine as a probable contributory mycotoxin in moldy forage mycotoxicoses.
Abstract: When infested with the fungus Rhizoctonia leguminicola, certain forages, e.g., red clover hay, can cause a "slobber syndrome" of varying severity when consumed by ruminants. The causative agent has been presumed to be slaframine [(1S,6S,8aS)-1-acetoxy-6-aminooctahydroindolizine], which is produced by R. leguminicola. In one serious outbreak of the slobber syndrome in horses, the red clover forage involved was carefully examined and found to contain R. leguminicola and slaframine. An identical hay sample is shown here by ion-exchange chromatographic and gas chromatographic-mass spectrometric analysis of appropriate hay extracts to also contain swainsonine [(1S,2R,8R,8aR)-1,2,8-trihydroxyoctahydroindolizine], a potent alpha-mannosidase inhibitor. Swainsonine has previously been isolated from pure cultures of R. leguminicola and from higher plants, namely the Darling pea (Swainsona canescens) and spotted locoweed (Astragalus lentiginosus). Consumption of Darling pea and spotted locoweed by livestock results in a severe neurological condition resembling that observed in hereditary mannosidosis in cattle and humans. Our findings indicate that swainsonine may be viewed as a mycotoxin when present in moldy forages consumed by livestock. The extent to which slaframine and swainsonine mycotoxicosis pose threats to animal husbandry and, indeed, to humans, if these alkaloids were to enter the human food chain, deserves serious consideration.
Publication Date: 1984-08-01 PubMed ID: 6435524PubMed Central: PMC241523DOI: 10.1128/aem.48.2.386-388.1984Google Scholar: Lookup
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- Journal Article
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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The research explores a condition termed “slobber syndrome” in ruminants, namely horses, caused by fungus-infested forages like red clover hay. The findings suggest a potent mycotoxin, swainsonine, in combination with slaframine, both produced by fungus Rhizoctonia leguminicola, as the probable contributors to this condition, warranting serious considerations on potential threats to animal husbandry and potential risks to humans through the food chain.
Introduction
- The study investigates the cause of “slobber syndrome” in ruminants which results in varying degrees of severity.
- It was suspected that the consumption of certain forages like red clover hay infested with the fungus Rhizoctonia leguminicola led to this condition in animals.
- Until now, the condition was attributed to slaframine, a product of R. leguminicola.
Research Process and Findings
- Detailed examination of red clover forage, closely associated with an outbreak of the syndrome, revealed presence of slaframine and R. leguminicola.
- The researchers utilized ion-exchange chromatographic and gas chromatographic-mass spectrometric analysis of hay extracts from the same forage sample.
- Through these studies, they identified the presence of another potent compound, swainsonine, an alpha-mannosidase inhibitor.
- Swainsonine has been previously known to be isolated from R. leguminicola and some higher plants such as Darling pea and spotted locoweed.
Impact of the Research
- The inclusion of swainsonine in the causative agents of the syndrome presents a new perspective, suggesting that it can be considered a mycotoxin when found in moldy forages consumed by livestock.
- As swainsonine’s consumption through higher plants in livestock leads to a severe neurological condition somewhat similar to hereditary mannosidosis in cattle and humans, it raises serious implications for animal husbandry.
- Furthermore, the study highlights the importance of investigating the impact on humans if these alkaloids were to enter the human food chain.
Cite This Article
APA
Broquist HP, Mason PS, Hagler WM, Harris TM.
(1984).
Identification of swainsonine as a probable contributory mycotoxin in moldy forage mycotoxicoses.
Appl Environ Microbiol, 48(2), 386-388.
https://doi.org/10.1128/aem.48.2.386-388.1984 Publication
Researcher Affiliations
MeSH Terms
- Alkaloids / analysis
- Animal Feed / analysis
- Animals
- Fermentation
- Gas Chromatography-Mass Spectrometry
- Poaceae
- Rhizoctonia / growth & development
- Swainsonine
Grant Funding
- AM16019 / NIADDK NIH HHS
- ES00267 / NIEHS NIH HHS
- ES00569 / NIEHS NIH HHS
References
This article includes 10 references
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Citations
This article has been cited 3 times.- Kagan IA. Blackpatch of Clover, Cause of Slobbers Syndrome: A Review of the Disease and the Pathogen, Rhizoctonia leguminicola. Front Vet Sci 2016;3:3.
- Ralphs MH, Welsh SL, Gardner DR. Distribution of locoweed toxin swainsonine in populations of Oxytropis lambertii. J Chem Ecol 2002 Apr;28(4):701-7.
- Das S, Gardner DR, Cook D, Creamer R. Analysis of the Mycotoxin Levels and Expression Pattern of SWN Genes at Different Time Points in the Fungus Slafractonia leguminicola. Microorganisms 2024 Mar 27;12(4).
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