Foodborne Intoxications ◾ 331
heat labile and can be destroyed in a contaminated food by high and uniform heat, such as 90°C for
15 minutes or boiling for five minutes. Radiation at 5–7 mrad can also destroy it.
Cell growth is necessary for toxin production. At optimum growth temperatures, toxins are
produced in large amounts. However, at both extreme growth ranges, enough toxins can be produced by a strain in a food to cause disease and death following ingestion.
Disease and Symptoms
There are five types of botulism: foodborne botulism, infant botulism, hidden botulism, wound
botulism, and inadvertent botulism.
Foodborne Botulism
Foodborne botulism is caused by the ingestion of the BoNT formed in a food (Figure 25.3).
The toxins are absorbed from the intestine and spread to the peripheral nerves, and they block
the transmission of impulse. However, at the initial stage (generally 12–36 hours, but it can be
two hours), some gastrointestinal disorders (e.g., nausea, vomiting, diarrhea, and constipation)
may be evident. Neurological symptoms develop within a short time, especially if the amount of
botulinum consumed is high. As they are highly potent toxins, only a very small amount (1 ng/kg
body weight) is necessary for severe symptoms and even death. In general, neurological symptoms
include blurred or double vision; difficulty in swallowing, breathing, and speaking; dryness of the
mouth; and paralysis of different involuntary muscles that spreads to the diaphragm, lungs, and
heart. Death usually results from respiratory failure.
Infant Botulism
Clo. botulinum spores, ingested by human infants through food, such as honey, and the environment, can germinate in the intestine and produce toxins to cause infant botulism. The spores fail
to produce the same disease, generally, in individuals above one year of age. In these individuals,
the well-established normal population of gastrointestinal microflora prevent spore germination
and cell multiplication by Clo. botulinum. Both types A and B have been identified in infant botulism cases. The symptoms consist of general weakness, inability to suck and control the head, loss
of reflexes, and constipation. Foods, such as honey and corn syrup, and dirt have been linked as
sources of Clo. botulinum spores in infant botulism cases.
Hidden Botulism
Hidden botulism, also known as the adult variant of infant botulism, is seen in adults suffering from
chronic gastrointestinal disorders, such as infectious bowel disease (IBD) or other gastrointestinal
abnormalities. This disease is called “hidden” because the source of toxin is not so obvious, and no
known food is linked to this disease. Clo. botulinum is almost always found in the feces, which aids in
diagnosis of this disease. 5 Besides Clo. botulinum, Clo. baratii has been implicated to cause this disease.
Wound Botulism
In wound botulism, spore-laden dust lodged in wounds as a result of a gunshot on the battlefield
or an accidental cut will germinate and produce toxins.
heat labile and can be destroyed in a contaminated food by high and uniform heat, such as 90°C for
15 minutes or boiling for five minutes. Radiation at 5–7 mrad can also destroy it.
Cell growth is necessary for toxin production. At optimum growth temperatures, toxins are
produced in large amounts. However, at both extreme growth ranges, enough toxins can be produced by a strain in a food to cause disease and death following ingestion.
Disease and Symptoms
There are five types of botulism: foodborne botulism, infant botulism, hidden botulism, wound
botulism, and inadvertent botulism.
Foodborne Botulism
Foodborne botulism is caused by the ingestion of the BoNT formed in a food (Figure 25.3).
The toxins are absorbed from the intestine and spread to the peripheral nerves, and they block
the transmission of impulse. However, at the initial stage (generally 12–36 hours, but it can be
two hours), some gastrointestinal disorders (e.g., nausea, vomiting, diarrhea, and constipation)
may be evident. Neurological symptoms develop within a short time, especially if the amount of
botulinum consumed is high. As they are highly potent toxins, only a very small amount (1 ng/kg
body weight) is necessary for severe symptoms and even death. In general, neurological symptoms
include blurred or double vision; difficulty in swallowing, breathing, and speaking; dryness of the
mouth; and paralysis of different involuntary muscles that spreads to the diaphragm, lungs, and
heart. Death usually results from respiratory failure.
Infant Botulism
Clo. botulinum spores, ingested by human infants through food, such as honey, and the environment, can germinate in the intestine and produce toxins to cause infant botulism. The spores fail
to produce the same disease, generally, in individuals above one year of age. In these individuals,
the well-established normal population of gastrointestinal microflora prevent spore germination
and cell multiplication by Clo. botulinum. Both types A and B have been identified in infant botulism cases. The symptoms consist of general weakness, inability to suck and control the head, loss
of reflexes, and constipation. Foods, such as honey and corn syrup, and dirt have been linked as
sources of Clo. botulinum spores in infant botulism cases.
Hidden Botulism
Hidden botulism, also known as the adult variant of infant botulism, is seen in adults suffering from
chronic gastrointestinal disorders, such as infectious bowel disease (IBD) or other gastrointestinal
abnormalities. This disease is called “hidden” because the source of toxin is not so obvious, and no
known food is linked to this disease. Clo. botulinum is almost always found in the feces, which aids in
diagnosis of this disease. 5 Besides Clo. botulinum, Clo. baratii has been implicated to cause this disease.
Wound Botulism
In wound botulism, spore-laden dust lodged in wounds as a result of a gunshot on the battlefield
or an accidental cut will germinate and produce toxins.