Clostridium botulinum

Hi everyone. My name is Dr. Sarah Fouch. Within this short recording, we will be considering Clostridium botulinum. As we work through the recording, we will consider the symptoms associated with a botulism infection and the virulence factors produced by this organism that are associated with the symptoms that patients may experience.

Let's consider Clostridium botulinum. This is a gram-positive bacillus. You can see here we have a gram stain of Clostridium botulinum, and again, they look like little tennis rackets. This is because the bacteria are starting to sporulate, and Clostridium botulinum sporulates at the end terminal. Now, these are fastidious organisms, which means they are not easy to grow. They can form their spores, and they are ubiquitous in nature, so it means they can be found everywhere. Now, if we think about spore-forming organisms, we very often see these in soil and water. Now, the Latin name botulus means sausage. Now, the image I've got there for you is actually showing you the organism sporulating, but you can see that we do have some bacilli within that gram stain, and actually, you can see they're quite sausage-shaped. Now, these are heterogeneous, which means they are non-uniform. Some can be very long, some can be short, some can be quite fat, and some can be skinny. Again, we find them everywhere. They are found in the soil and the water. There are four groups of Clostridium botulinum. Most human diseases are caused by Type I or Type II. But again, Clostridium botulinum can produce toxins, and we have seven distinct toxins: A, B, C, D, E, F, and G; but, only one toxin is produced per type, and the toxins are produced as the bacteria are sporulating. Now, when we think about the clinical syndromes, we have a number of different clinical syndromes. Good examples here are foodborne botulism, infant botulism, and wound botulism. In the next slides, we'll consider each of these types of botulism and the symptoms that are associated with them.