Growth

• Clostridium botulinum grows best in a low-oxygen environment. The spores of these bacteria can survive for a long period in a dormant state until they are exposed to suitable conditions.
  
  

Types of Toxin

• There are seven types of botulinum toxin produced by different strains of Clostridium botulinum. These types have the designations A through G, although types A, B, E and F are the only ones especially toxic to humans.
  
  

Frequency of Botulism

• There are approximately 145 cases of botulism reported in the United States each year. Infant botulism comprises 65 percent of these cases, 20 percent of botulism cases are wound-related and 15 percent are caused by eating contaminated food.
  
  

Signs of Botulism

• Botulism causes general weakness in the facial muscles, drooping eyelids, slurred speech and difficulty swallowing.
  
  

Diagnosis of Botulism

• The most direct way to diagnose is to inject the patient's serum or stool into mice and look for signs of botulism in the animal. Clostridium botulinum can also be isolated and identified from blood and stool samples.