Botulism - a Case Study

Every year, about 110 cases of botulism are reported in the United States. About 25% of the cases result from food, while 72% are infant botulism and 3% are wound botulism. Food-borne botulism is usually caused by eating home-canned foods that are contaminated with the toxin botulin. Botulin is produced by Clostridium botulinum, which is the name of a group of bacteria commonly found in soil. The bacteria grow best in low-oxygen conditions. The bacteria form spores that enable them to survive in an inactive state until exposed to conditions that may support their growth (for instance, a vegetable). There are seven types of the botulin toxin, but only four of the seven types cause illness in humans.

The Nervous system and the muscular system are two organ systems primarily affected by botulin intoxication. The nervous system is affected when the botulin toxins bind to the presynaptic membranes at the motor end places, causing a chain reaction, which inhibit the release of acetylcholine. Symptoms such as double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness clearly illustrate a correlation between botulism and the muscular system.

Synaptic transmission at a motor end plate normally begins when a nerve impulse reaches a synaptic terminal. Synaptic vesicles then travel towards and combine into the presynaptic cell membrane of the motor neuron. This stimulates the release of acetylcholine, which diffuses across the synaptic cleft and binds to receptors on the postsynaptic cell membrane of a muscle fiber. When a botulin enters a human, the toxin binds to the presynaptic membranes at the motor end plates to prevent the release of acetylcholine from the motor neurons. This inhibits synaptic transmission and muscle contraction.

Sarah’s symptoms included: blurred vision, the inability to focus, difficulty swallowing, slurred speech, and difficulty breathing. These symptoms occurred due to Sarah’s lack of muscle control. The botulin binds to the presynaptic membranes at motor end plates, which inhibits the release of acetylcholine. Because the acetylcholine is prevented by the botulin toxins from