Infectious Diseases Unit 4 Lesson 1 plan

1. Infectious Diseases • Unit 4 Lesson 1 plan

2. Do now • Brainstorm: • Once microbes get in, how do they make us sick?

3. How pathogens damage the host? • Direct damage • When the pathogen replicates. • When the pathogen releases factors like toxins. • Indirect damage • When the immune response is activated. • Pathogensoften use the immune response to cause damage that benefits themselves.

4. Where can bacteria replicate? • Extracellular: • Outside of cells. • Intracellular: • Inside of cells.

5. Bacteria replicating inside cells

6. Where pathogens replicate influences the type of infection they cause Replicating extracellularlymeans adaptability

7. Where pathogens replicate influences the type of infection they cause Replicating intracellularlymeans protection from the environment Chlamydia trachomatis is the leading cause of bacterially transmitted STDs – 4 million cases in the US annually Chlamydia detected With a green antibody.

8. How chlamydia replicates inside cells EB Non-invasive Form outside Cells is EB RBs convert back to EBs to leave the cell Invasive EB form enters epithelium Starts again when Nutrients present Modifies itself Into RB form - can’t be destroyed RB Stops if immune system stimulated Stops if nutrients run out

9. How might the rate a pathogen replicates impact the illness it causes?

10. How fast pathogens replicate also influences the type of infection they cause Replicating quickly causes an acute illness Sack et al., 2004 Vibrio cholera

11. How fast pathogens replicate also influences the type of infection they cause Replicating slowly causes the illness to persist Mycobacterium tuberculosis

12. How tuberculosis persists

13. Wrap up • We get sick because our cells are damaged!

14. Homework • Read about how bacteria produce toxins for the next class.