Biotoxins
The term "biotoxin" is sometimes used to explicitly confirm the biological origin.
Toxins produced by microorganisms are important virulence determinants responsible for microbial pathogenicity and/or evasion of the host immune response.
Biotoxins vary greatly in purpose and mechanism, and can be highly complex (the venom of the cone snail contains dozens of small proteins, each targeting a specific nerve channel or receptor), or relatively small protein.
Biotoxins in nature have two primary functions:
- Predation (spider, snake, scorpion, jellyfish, wasp)
- Defense (bee, ant, termite, honeybee, wasp, poison dart frog)
Some of the more well known types of biotoxins include:
- Cyanotoxins, produced by cyanobacteria
- Hemotoxins target and destroy red blood cells, and are transmitted through the bloodstream. Organisms that produce hemotoxins include:
- Pit vipers, such as rattlesnakes
- Necrotoxins cause necrosis (i.e., death) in the cells they encounter and destroy all types of tissue. Necrotoxins spread through the bloodstream. In humans, skin and muscle tissues are most sensitive to necrotoxins. Organisms that possess necrotoxins include:
- The brown recluse or "fiddle back" spider
- The "Puff Adder" - Bitis arietans
- Necrotizing fasciitis (the "flesh eating" bacteria)
- Neurotoxins primarily affect the nervous systems of animals. Organisms that possess neurotoxins include:
- The Black Widow and other widow spiders
- Most scorpions
- The box jellyfish
- Elapid snakes
- The Cone Snail
- Cytotoxins are toxic at the level of individual cells, either in a non-specific fashion or only in certain types of living cells:
- Ricin is a plant toxin found in the castor bean plant
- Apitoxin, the honey bee venom
- Mycotoxins are toxins produced by fungi. They are a common source of toxins in grains and other foods.
- Eosinophil derived neurotoxin is a toxin found in human encoded by the RNASE2 gene. it is found only in eosinophils
Read more about this topic: Toxin