BOTULISM FOR THE LAYMAN

There are basically two types of bacterial food poisoning. In the
first type, called a food-borne infection, the bacteria are present
in the food and after the food is eaten the bacteria multiply in the
digestive system and cause illness. That is, the bacteria itself, as it
multiplies in your system, makes you ill. In the other type of food
poisoning, called food intoxication, the bacteria is also present in
the food. But with this type, the bacteria multiply in the food and
as it does it manufactures poisons which are called toxins. When
the contaminated food is eaten, it is not the bacteria, but the toxin
that causes the illness.

Botulism is a food intoxication. The bacteria, Clostridium botulinum,
are found everywhere in the soil and in water. The bacteria and its
spores are harmless, they live in the soil for years and we eat them
on raw fruits and vegetables everyday - with no ill effects. It is only
when the botulism bacteria spores begin to grow in the absence of
air that they produce a toxin which causes illness and usually death
when eaten. Botulism toxin is produced only in contaminated food
and the toxin must be swallowed, it cannot be produced in the body.
It is only in the absence of air that botulism spores grow and produce
poison and an ideal environment is home canned products, or
commercially vacuum sealed cans or plastic packages if they are not
processed and handled properly.

Temperature is an important factor in the growth of botulism spores
and production of toxins: growth of botulism spores is fastest
at about 100°F and they grow in the range of 40° to 115°F.

Botulism bacteria do not compete well with other types of bacteria.
Where other bacteria are allowed to multiply, botulism spores will not
grow. Underprocessing, e.i., insufficient heating to destroy all the
botulism spores present, is extremely dangerous. For example, if the
process calls for heating at 240° to 250°F for 35 minutes, processing
for any less time would be underprocessing. Underprocessing may
allow sufficient time to kill other bacteria that compete with botulism
thus allowing the botulism spores to grow and produce toxin.

Understanding the facts about botulism food poisoning are important
because the toxin is often fatal and is difficult to detect. Sometimes,
botulinum contaminated cans or jars will bulge or have off odors,
but such is not always the case. It is common for a botulism
intoxicated food to appear and smell normal. NEVER taste a food
"to be sure" .... BOIL the food for 10 minutes first. Botulism toxin
is so potent that ½ a pound could eliminate the entire world
population. Merely licking a finger containing toxins can be fatal.
The rule is .... "When in doubt, throw it out!"

Botulism toxin can be destroyed be maintaining a temperature of
212°F (the temperature at which water boils) for 10 minutes.
Boiling will inactivate the toxin but botulism spores can survive
both the exposure to air and the boiling. If the surviving spores
are then placed in an air-tight container they can produce toxins.
Botulism spores can be killed in a reasonable length of time only
by heating at temperatures of 240° to 250°F. To obtain such a
high temperature, steam under pressure (i.e., a pressure cooker
with a properly adjusted temperature and pressure gauge) must
be used. How long canned food must be heated at 240° to 250°F
depends on the type of food and the size of the jar. Tested canning
instructions for each type of food should be followed carefully.

To summarise, the following is a list of the conditions
under which botulism grows best:

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Updated: 04/13/2000