HSS 1100 Lecture Notes - Lecture 5: Clostridium Botulinum, Virulence Factor, Exotoxin

• School: University of Ottawa
• Department: Health Sciences
• Course: HSS 1100
• Professor: William Yan

Document Summary

Bacillus anthracis is the causative agent of anthrax: unique protein capsule, antiphagocytic. Major virulence factor: aerobic growth conditions, spores are very stable, resistant to heat, drying, uv, and disinfectants toxins are made only when spores germinate. Spores are only formed when conditions become unfavourable. Spores cannot grow or multiply: humans exposed to spores usually through contact with animals or soil, used in bio-terrorism and warfare, exotoxin encoded on pxo1 plasmid. Plasmid contains virulence factors which are transcribed optimally at. Exotoxin is composed of 3 proteins: edema factor (ef), protective antigen (pa), lethal factor (lf) Proteins on their own are not toxic. Both plasmid required for virulence: rapid treatment is essential, antibiotics: penicillin, doxycycline, ciprofloxacin, levofloxacin, vaccine against pa protein is available. Not administered unless in high risk population. Bacillus cereus: causes food poisoning when spores enter food product (often rice, motile, non-encapsulated, resistant to penicillin, enterotoxin is responsible for illness. Heat labile: nausea, abdominal pain, diarrhea, lasts 12-24h.