You and Your Microbes
You will have no other relationship so intimate as the one you have with your microbes. You have more microbes on and in you than you do your own cells. So who really is in charge of whom? Much focus is on the pathogens, those microbes that make us sick. And of course we should control for them to make us well. But should we be interfering with the microcommunity that lives on and in us on a daily basis?
There is evidence to support that miscommunications between our microbes and our cells can result in such things as autoimmune diseases. The overuse of antibiotics in children has also been shown to result in an imbalance in our bacterial flora as adults; this can result in digestive disorders. It has been also been found that transferring “good” digestive bacteria to people that have Crohn’s Disease can significantly relieve intestinal flare ups.
Maybe we should be protecting the microbial community that is on and in us instead of being “germophobes”. Should we be using antibacterial products in our everyday lives? In our homes, offices, and schools? How well do they work anyway? Good question.
The purpose of our inquiry experiment is to determine the effects of everyday cleaners and soaps have on our microbial community.
You will be given access to the following materials: nutrient agar plates, various household soaps and cleaners, antibacterial discs, plain discs, and a 32C incubator.
With a small group or partner you will develop a hypothesis and design a mini experiment to test it. Below are some examples:
1. Handwashing with soap is as affective at inhibiting bacteria growth as using hand sanitizer.
2. Handwashing with soap is not as affective at inhibiting bacterial growth as using hand sanitizer.
Important things not to forget
1. Can you keep a control? Can we just have a class control?
2. Write your names, hypothesis, and procedure on a separate piece of paper.
3. Write with a sharpie on the bottom of your plate.
4. You can divide a plate with a sharpie in halves or quarters.
5. You can use sterile swab (or cotton ball). Wet it and microwave it. Choose something/someone to sample.
6. You may only sample in the room.
7. People are always great sources of bacteria (If you choose to sample fingers for handwashing you can just gently touch the agar – no need for a swab).
8. Add antibacterial discs if needed.
9. If you have discs you will incubate right side up. If you have no discs, you will incubate upside down.