Lab 8:  Objectives

Concepts:  Quizzes and Practicals

1. How does UV light affect microorganisms (specifically—ie not just that they die)?  What does UV light do to them?  Describe how this happens.
2. What type of UV light is biocidal?  What types can damage DNA?
3. Why can Bacillus survive better than Staphylococcus when exposed to UV?
4. Why can’t UV light penetrate the paper that you placed on ½ of the plate?
5. What type of radiation is UV light?
6. Define and be able to identify examples of the following:
   1. Antibiotic
   2. Disinfectant
   3. Antiseptic
   4. Chemotherapeutic agent
7. Know how the Disk diffusion method (AKA Kirby-Baur test) is used to test for the effectiveness of different antibiotics.
8. Why is Pseudomonas aeruginosa resistant to many antibiotics? (look in your lecture text book).
9. Know the difference between a narrow spectrum and a broad spectrum antibiotic.
10. How does drug resistance occur and how can it be prevented?
11. Know the difference between antibiotic sensitive, intermediate and antibiotic resistant.
12. Compare and contrast bacteriocidal and bacteriostatic agents (how are they similar and how are they different)
13. Put the following in order of most resistant to least resistant to chemical agents:
    1. Bacillus megaterium
    2. Escherichia coli
    3. Pseudomonas aeruginosa
    4. Staphylococcus aureus

Skills/Identify:  Practical

1. Be able to measure zones of inhibition and relate the zone size to resistance and susceptibility using a chart.