Friday, April 15, 2016

Mystery TSA Dish Bacteria Example Post by Gwen

Here is a very simple example of what I expect to see for the Mystery TSA Dish Bacteria experiment. Please feel free to be more creative!
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Here are the photos for my Mystery TSA bacteria experiment:


Day 0: 
I wanted to see if the men's bathroom had more bacteria than the women's bathroom. I hypothesized that women would be likely to wash their hands more often and handles would be cleaner. Lisa, my assistant, took a swab of the sink faucet and toilet handle for both bathrooms on the 2nd floor of Brier. We made two duplicate dishes and one was stored at 24°C (room temperature) and the other was stored at 37°C (body temperature).

Day 2:
On day two I examined both my dishes and surprisingly there was no growth. I was sure there would be some growth at room temperature and possibly growth at boy temperature because one would assume many body-associated microbes would be found in the bathroom! Perhaps Edmonds CC students are very good at washing their hands!

Day 7:
Finally, there was some growth on the 37°C dish. Unfortunately my 24°C dish appears to have been taken or lost, so I am unable to tell you what exciting bacteria grew on that dish. For the 37°C plate there was only growth on the area where Lisa took a swab of the faucets in both bathrooms but no growth on the toilet handle samples. I found a cool website with terms for describing bacteria/yeast/mold colonies on media.On the sample from the men's bathroom faucet there were 5 colonies or plaques of what appeared to be the same species- a smooth yellow, raised circular growth. 
The sample from the women's bathroom was similar but the colonies were lighter yellow and they were more plentiful- 22 raisedcircular yellow colonies! I believe the larger one shown below was the same species/type but I am not sure. I looked at them closely under a dissecting scope but I was unable to discern if this one large colony was a different species.


Day 7 Growth, Women's bathroom faucet sample, 37°C.
I tried to figure out what the bacteria were by looking at some microbe galleries online, like this medical microbe gallery and this academic guide, but of course it is difficult to identify. My best guess is that the bright yellow growth from the men's faucet could be a type of Staphylococcus sp. (common and associated with respiratory colds). It looks like my assumptions were wrong. Toilet handles were not covered in bacteria like I thought and Men's bathrooms did not have more bacteria on their handles than the women's bathroom!

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