distinction based on human behaviour and not on the chemistry, bio-
chemistry or toxicology of the compounds.
There are relatively few species of agarics which can be considered as
deadly poisonous but they include the deathcap,Amanita phalloides,a
quarter of a cap of which can be lethal to a healthy adult, and species of
Cortinarius which are still foolishly mistaken for edible wild fungi
(Figure 8.8). In both these cases the toxins cause irreversible damage
to the liver and kidneys and death may follow several weeks after the
initial consumption of the poisonous fungi.
It is worth emphasizing a major difference between the toxic met-
abolites of fungi and the toxins of most of the bacteria associated with
food poisoning. The former are relatively low molecular weight com-
pounds, although their chemistry may be very complex, while the latter
are macromolecules such as polypeptides, proteins or lipopolysaccha-
rides. An exception to this generalization is an unusual bacterial food
poisoning associated with a traditional food produced in parts of Indo-
nesia; a form of tempeh is made by inoculating coconut flesh with
moulds such asRhizopusandMucor. Occasionally the process becomes
contaminated with the bacteriumBurkholderia cocovenenans, previously
known asPseudomonas cocovenenans, which produces at least two low
molecular weight toxic metabolites, bongkrekic acid and toxoflavin (see
Chapter 9).
Although there are many genera of moulds which include toxigenic
species three stand out as especially important –Aspergillus, Penicillium
andFusarium.
8.4.2 Mycotoxins ofAspergillus
8.4.2.1 The Aflatoxins. In 1959 a very singular event occurred which
initiated the international interest which now exists in mycotoxins. This
was the deaths of several thousand turkey poults and other poultry on
farms in East Anglia and, because of the implications for the turkey
Table 8.1 Toxic compounds of some ‘toadstools’
Toxin Species Toxic effects
Coprine Coprinus
atramentarius
Considerable discomfort when consumed
with alcohol
Illudin Omphalotus olearius Gastrointestinal irritation Vomiting
Amatoxin Amanita phalloides Liver and kidney damage, death unless
treated
Orellanin Cortinarius orellanus Irreversible kidney damage, death or very
slow recovery
Psilocybin Psilocybe cubensis Hallucinogenic
Muscarine Inocybe patouillardii Vomiting and diarrhoea
282 Non-bacterial Agents of Foodborne Illness