1. Attack of the Superbugs Lab Introduction
Mrs. Stewart
Medical Interventions

2. Superbugs What is a “superbug”?
Bacteria that have become stronger and less responsive to antibiotic treatment

3. How can bacteria share resistance?
Genetic Transfer Method
Description
Conjugation
The one-way transfer of DNA (plasmid) between bacteria in close cellular contact
Transformation
The genetic modification of a bacterium by incorporation of free DNA from the surrounding environment (usually caused by another ruptured bacterial cell)
Transduction
The transfer of genetic material from one bacterium to another by a genetic vector (bacteriophage virus)

4. This lab uses 2 types of Bacteria:
E. coli I
contains a gene found on the chromosomal DNA coding for streptomycin resistance
E. coli II
contains a gene found on the plasmid DNA coding for ampicillin resistance.

5. Predict
What will happen when the E. coli I strain is mixed with the E. coli II strain?

6. Lab Materials: 4 growth plates
LB Agar
LB + Str
LB + Amp
LB /Str /Amp
*LB Agar = growth medium for bacterial cells

7. Lab Day 1: Obtain 2 of each type of growth plate
Streak E. coli I on 4 plates
Streak E. coli II on 4 plates
Incubate overnight
*These will be the confirmation plates

8. Evaluate
What are we confirming?

9. Lab Day 2: Observe confirmation plate results Prepare “mix” plate
You will literally be mixing the two types of bacteria together onto one plate
Incubate overnight

10. Evaluate
Why are we mixing them together?

11. Lab Day 3:
Use new “mixed” bacterial cultures and spread onto the 3 types of antibiotic plates

12. Predict
What would you expect to see on these growth plates?
Why?

13. FRIDAY – Lab Day 4
You must come in at some point during the day Friday to observe and record your results
Remember: Pictures of lab results will be required in your lab reports
*Growth plates will be discarded at 3:10 pm on Friday. Any results not recorded will be lost.

14. Student Lab Schedule
Day:
Time Needed:
Activity:
How to Store:
Additional Info:
Lab Day 1
~ 30 minutes
Students prepare confirmation plates.
Invert the plates, label, and incubate at 37˚C for 24 hours.
(1) Students complete steps 1 – 33 on P
(2) Students work through the mechanisms of antibiotic resistance animations.
Lab Day 2
Students observe confirmation plates and prepare “Mix Plate.”
(1) Students complete steps 34 – 47 on P
(2) Students begin construction of 3-D model.
Lab Day 3
Students streak cultures from “Mix Plate” onto antibiotic plates.
(1) Students complete steps 48 – 60 on P
(2) Students continue construction of 3-D model.
Lab Day 4
~ 10 minutes
Students make observations of plates to test for antibiotic resistance.
Clean-up all materials.
(1) Students complete steps 61 – 65 on P
(2) Students complete work on 3-D models and present models to class.
(3) Students answer all remaining Conclusion questions.