bacterial horizontal gene transfer
. Web research on an antibiotic (listed below)
2. CDC Website on antibiotic resistance http://www.cdc.gov/getsmart/antibiotic-use/antibiotic-resistance-faqs.html
3. Video on MRSA (10 min) https://www.youtube.com/watch?v=GBPQL6NcsiM
4. Application Assignment Rubric
Instructions:
• Review the sections on natural selection, antibiotics, and bacterial horizontal gene transfer in your text
• Perform web research on an antibiotic mode of action
• Read the CDC website on antibiotic resistance
• Watch the video on MRSA and the spread of antibiotic resistance
• Respond to six prompts (1-6) in a single MS Word document, using complete sentences. Your response for all the eight prompts combined should be at least 200 words for full credit. Please review the Application Assignment rubric for detailed expectations as your responses will be evaluated for completeness, content, comprehension, clarity, and citation.
• Upload your responses to the appropriate area by the due date specified in the Course Schedule section of the Syllabus.
Introduction
As a society, we have come to rely on antibiotics to treat bacterial infections. The ability of antibacterial chemicals to specifically kill bacterial cells and not harm your own cells comes from the differences between your eukaryotic cells and prokaryotic bacterial cells.
For example, take the following common antibiotics: penicillin, polymixin, rifamycin, and erythromycin. See “Apply it now: Antibiotics and other Germ Killers,” Ch 17 to learn how these chemicals work to inhibit bacterial growth.
Unfortunately, the antibiotics that were once “wonder drugs” are rapidly losing their effectiveness. Visit the CDC website on antibiotic resistance to learn more about antibiotic resistance in bacteria. Note in particular the sections on “Why are bacteria becoming resistant to antibiotics?” and “How do bacteria become resistant to antibiotics?” , and you will recognize the process of natural selection and evolution at work. One example of a type of bacteria that has adapted resistance to antibiotics if Methicillin-Resistant Staphylococcus aureus, or MRSA. Watch this 10-minute video on MRSA to learn about how resistance genes can be transferred between bacteria.
Prompts:
11. Look up the mechanism of action for one of the following antibiotics: Penicillin, Polymixin, Rifamycin, or Erythromycin. Briefly describe how this antibiotic targets a feature of bacterial cells that is absent or significantly different from features of cells in Domain Eukarya, using appropriate sources and citations. Why can’t a viral infection be treated with these antibiotics?
12. Describe the requirements for natural selection and the process of evolution, using antibiotic resistance in bacteria as an example. In your response, address the following questions: Where does genetic variation come from? How have humans introduced an environment that selects for resistance? How do antibiotics introduce a difference in reproductive success among the bacteria?
13. Describe the resulting change in the population after antibiotic selection—is this an example of directional, disruptive, or stabilizing selection?
14. What are “commensal bacteria” and where are they found? Briefly explain how horizontal gene transfer could lead to antibiotic resistance spreading from commensal bacteria to pathogenic, disease-causing bacteria. (see Ch 17.2D)
15. What does Dr. Christina Burch recommend in the MRSA video to help slow the spread of antibiotic resistance from our commensal bacteria to potential pathogens?
16. Using information from the CDC website on antibiotic resistance , video on MRSA , or other sources, describe at least one other important approach you could take to help stem the spread of antibiotic resistant bacteria.
