1. One Staphylococcus cell lands in a bowl of gravy. This organism has a
generation time of 15 minutes. How many bacteria would be in the bowl of gravy
after one hour.
2. Ziggy Stardust was making her famous vegetarian spaghetti sauce for a potluck party. Before putting the sauce into the container to carry to the party, Ziggy stuck her finger into it to get a little sample to taste. It tasted good!!! So Ziggy tasted the sauce one more time using the finger technique. Ziggy's finger deposited about 10,000 staphylococci into the sauce. Given a generation time of 15 minutes and 2 hours until the party, how many organisms could be in the sauce by the time the party starts.
The party lasts two hours and the serving dish would sit out on the counter for that amount of time. How many organisms could be in the sauce at the end of the party?
How could refrigeration affect this problem? Why?
How could heating affect this problem? Why?
What are some of the parameters that affect the growth of bacteria?
3. Describe the structure of the skin. How thick is skin? How many layers deep is the "dead" layer? What is apoptosis?
Here are a few links that might help you with this term:How does the skin protect itself from attack by bacteria?
Would normal flora help in this protection?
4. What is the difference between the normal flora and the transient flora of the skin?
Where do pathogens fit into these two categories of organisms?5. This is an open ended question --- Handwashing is probably the single most effective means available to control the spread of infection both in the hospital and outside of the medical setting. Yet numerous studies indicate that people don't wash their hands as often as they should.What are opportunistic pathogens?
How do bacteria manage to attach themselves to the skin?
How does handwashing affect the normal flora?
How does handwashing affect the transient flora?
Can one ever remove all the flora from the skin?
What is the point of a surgical scrub?
Why do you think this is so?6. Go out and find 5 different antibacterial soaps or mouthwash items and determine what the active ingredient is. (It should be stated on the label.)What could be done do you think to bring people around to washing their hands more often?
How does each of these ingredients work?7. The figure shows the results of a handwashing experiment with a new brand of hand soap. Each of the letters represents a colony type. Describe and explain the results for each colony type (and don't forget k.)For instance here are a few links for triclosan:
- http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10398587&dopt=Abstract
- http://www.brooks.af.mil/dis/DIS54/sec2d1.htm
- http://www.cqs.com/total.htm
- http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10477976&dopt=Abstract
- http://www.vitaletherapeutics.org/~galenvtp/vtltclxn.htm
- http://news.bbc.co.uk/hi/english/sci/tech/newsid_145000/145955.stm
- http://www.seattletimes.com/news/health-science/html98/altbact_080698.html
8. How is wine made? What do you start with?
What happens during the transformation from starting substance to finished substance?9. What is the medical importance ofWhat is the name of the organism involved?
Candida albicans,What is the significance of these organisms in HIV/AIDS disease?Pneumocystis carinii,
Cryptococcus neoformans?
What about in non-immunodeficient individuals?
10. What are some of the skin diseases caused by Staphylococcus aureus? Streptococcus pyogenes?
11. What is a nosocomial infection? Why are these types of infections a worry?
12. Molds and yeasts are both fungi. How are they different? What is a dimorphic fungus? Name some infections are caused by dimorphic fungi.