Related Experiment Videos
Studies of the toxicity of Helminthosporium maydis
Abstract:
Isolates of Helminthosporium maydis from blighted corn were tested for toxicity in mice, rats, swine, rabbits, microorganisms, and tissue culture. Extracts of grains, mycelia, and culture supernatant fluids killed mice on intraperitoneal (ip) injection, but were nontoxic on administration by mouth to swine. The toxin was partially purified and appears to be a glycophospholipid. Histopathological examination revealed that the toxin acted as a severe irritant on ip injection, causing death in laboratory animals. In skin tests with rabbits, considerable exudation occurred, rather than necrosis.
Insights
Toxin extracts from Helminthosporium maydis, a corn blight pathogen, proved lethal to mice via intraperitoneal injection but safe for swine orally. The potent irritant, identified as a glycophospholipid, caused significant exudation in rabbit skin tests.
Area of Science:
- Agricultural Science
- Toxicology
- Microbiology
Background:
- Helminthosporium maydis causes significant crop losses in corn (maize).
- Understanding the pathogenicity and toxicological effects of H. maydis is crucial for agricultural safety and animal health.
- Previous research has indicated potential toxicity, but the specific nature and effects of the toxin require further elucidation.
Purpose of the Study:
- To evaluate the toxicity of Helminthosporium maydis isolates in various animal models and in vitro systems.
- To characterize the toxic compound produced by H. maydis.
- To determine the mechanism of toxicity, particularly the irritant and necrotizing potential.
Main Methods:
- Toxicity testing of H. maydis extracts (grains, mycelia, culture supernatant) in mice, rats, swine, and rabbits.
- Oral administration studies in swine.
- Partial purification of the toxic compound.
- Histopathological examination of affected tissues.
- Skin irritation tests in rabbits.
Main Results:
- Intraperitoneal injection of H. maydis extracts was lethal to mice.
- Oral administration of the extracts to swine showed no toxicity.
- The toxic agent was partially purified and identified as a glycophospholipid.
- Histopathology confirmed the toxin acts as a severe irritant upon intraperitoneal injection, leading to animal death.
- Rabbit skin tests demonstrated significant exudation, not necrosis, indicating an irritant rather than a necrotizing effect.
Conclusions:
- Helminthosporium maydis produces a toxic glycophospholipid that is lethal to mice via intraperitoneal injection due to severe irritation.
- The toxin's route of administration significantly influences its toxicity, with oral exposure in swine being non-lethal.
- The findings highlight the importance of understanding toxin delivery and host response in the pathogenicity of H. maydis.