HSS 1100 Lecture 5: Lecture 5 - Gram Positive & Negative Bacilli

• School: University of Ottawa
• Department: Health Sciences
• Course: HSS 1100
• Professor: Franco Pagotto

Document Summary

Vegetative bacteria: some can form thick layer outside of nucleic acid, called a spore. Does not grow & divide, in a cocoon. 4 are rods (2 spore-formers and 2 non- Humans usually exposed to spores during direct contact with infected animals and/or soil. Spores of b. anthracis very stable, resistant to drying, heat, ultraviolet light, disinfectants. Germination and expression of plasmid encoded virulence factors (on plasmids pxo1 and pxo2) is regulated by increase in temperature to 37 c, co2 increases, and serum protein [spores activate only when introduced into a host] Used for biological terrorism and warfare (japanese army in manchuria in 1940) spore-formers: anthracis exotoxin: They cause disease by the release of potent exotoxins. They differ biochemically by the ability (or lack thereof) to grow in the presence of oxygen. o. Bacillus likes oxygen (aerobic); whereas clostridium grows in the absence of oxygen (anaerobic)