Question
Mycotoxins.
Answer
Mycotoxins are toxic secondary metabolites produced by certain fungi (moulds), particularly when growing on stored food grains, nuts, and other agricultural commodities under conditions of poor storage (warm, humid conditions), which can cause disease (mycotoxicosis) in humans and animals following ingestion of contaminated food, rather than through direct fungal infection.
Important examples:
- Aflatoxins — produced by Aspergillus flavus and A. parasiticus, contaminating improperly stored groundnuts, maize, and other grains; aflatoxin B1 is a potent hepatocarcinogen, strongly implicated (especially in combination with chronic hepatitis B infection) in the pathogenesis of hepatocellular carcinoma in endemic regions; acute high-dose exposure can cause acute hepatotoxicity.
- Ochratoxin A — produced by Aspergillus and Penicillium species, nephrotoxic, implicated in Balkan endemic nephropathy.
- Ergot alkaloids — produced by Claviceps purpurea, a fungus infecting rye and other cereals; causes ergotism, historically presenting with vasospasm/gangrene (“St. Anthony’s fire”) or convulsive symptoms following ingestion of contaminated grain/flour.
- Trichothecenes (e.g., T-2 toxin) — produced by Fusarium species, causing gastrointestinal and haematological toxicity.
- Zearalenone — a Fusarium mycotoxin with oestrogenic effects.
Clinical/public health significance: mycotoxin contamination of staple food crops (especially groundnuts and cereals in tropical/subtropical regions with poor storage infrastructure) is an important food-safety and public-health concern, contributing to acute poisoning outbreaks and long-term cancer risk; regulatory food-safety programmes set permissible limits for aflatoxin and other mycotoxin contamination in food and animal feed.