Microbiology and Immunology 2500A/B Lecture Notes - Gut Flora, Clostridia, Botulinum Toxin
Document Summary
Clostridia form endospores and vegetative cells are killed by oxygen. They are generally found in soil and intestinal tracts of animals. Clostridia are responsible for several unrelated diseases, as there are over 80 species of clostridia (most which are not pathogenic). The above can cause life-threatening diseases mediated by exotoxins. Endo means within, and endospores are highly resistant to heat, drying, harsh chemicals, and nutrient depletion. They function as survival structures and are also used for dispersal through air, water, and intestinal tracts. Endospore formation is best studied in bacillus and clostridium species. Sporulation occurs due to a lack of nutrients and stress development of endospores. Endospores are considered a dormant stage in the bacterial life cycle and can remain dormant for years, but revert back to vegetative cells rapidly. Endospore formation occurs through c complex series of events: The exosporium and spore coat are composed of protein. The cortex contains dna, cytoplasm, ribosomes, etc .