Infectious Agents

Learning Objectives

1. Explain the major differences between prokaryotic and eukaryotic cells
2. List major types of infectious agents and be able to distinguish between living and non-living
3. Explain key differences among bacteria, fungi, protozoa, and prions
4. Describe how bacteria and viruses reproduce
5. List and describe the four general patterns of viral infection
6. Define 'prion' and discuss the role of prions in the epidemic of bovine spongiform encephalopathy (BSE) in the UK
7. Discuss the role of prions in Creutzfeldt-Jakob Disease (CJD)
8. Discuss how the British BSE epidemic in cattle caused disease in humans

The 5 Kingdoms

Every species can be categorized as a plant, animal, bacteria, fungi, or protozoa. While natural selection implies competition among and within species there is a strong interdependence among species. For example, most bacteria are non-pathogenic and live in and outside our bodies and provide many benifits, such as preventing pathogenic species from gaining a foothold.