Mystery TSA Dish Bacteria
Blog by Shawna Steele
Day 0
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| Figure 1. TSA Dishes at the beginning of experiment. Dish on the left was incubated at body temperature (37 degrees) and the dish on the right was incubated at room temperature (24 degrees). |
At the start of this experiment, I really wanted to see what was growing on me as well as what was growing on things I use every day, like my cellphone. I was part of the group in class that read about Lady Gaga's belly button so I thought I would investigate what was growing in mine since so many different kinds of bacteria can live in there. I also took a sample from my mouth because I know that the human mouth can be a home for so many bacteria, especially since they are not the cleanest part of body (despite the brushing and flossing). I also took a sample from my cellphone and the men's bathroom door handle since I was curious to see how clean (or not) men really are. I hypothesized that my belly button would grow the most bacteria mainly because of that cool study and article I read about. I also predicted that my cellphone would be pretty dirty since I don't really clean my phone.
Day 2
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| Figure 2. TSA Dish incubated at 37 degrees results on Day 2. |
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| Figure 3. TSA Dish incubated at 24 degrees results on Day 2. |
On the second day of observing, I noticed that the dish that was incubated at body temperature had more growth than the dish that was incubated at room temperature. My belly button showed the most growth out of both plates, but was most noticeable on the plate that was at body temperature. This makes since bacteria in the belly button would grow better at a temperature similar to the temperature of my body than of a room. There was also some bacteria growth from my cellphone at body temperature as well which was interesting to see since bacteria in my mouth at body temperature had little to no growth although there was growth of mouth bacteria on the room temperature plate. Also surprisingly for both plates, there was no evidence of bacterial growth on either plates from the men's bathroom door handles. This could be because of our school's good practice of washing their hands or using antibacterial cleaning solutions to wipe off germs from these surfaces.
Day 7
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| Figure 4. TSA Dish incubated at 24 degrees results on Day 7. |
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| Figure 5. TSA Dish incubated at 37 degrees results on Day 7. |
Found it interesting that just by looking at colors it appears that your cell phone had more different types of bacteria on it than your navel. I imagine that with all the growths in the belly button bacteria there are actually more types in it, but to the naked eye the cell phone wins. I wonder how much more bacteria people with an innie belly button than an outie.
ReplyDeleteHi Shawna,
ReplyDeleteI find your results very interesting, since I tested my mouth and cell phone as well. I found the same pattern of many colonies and less growth in my mouth sample, although my mouth sample grew better at body temperature. Contrary to your results, only one tiny colony grew from my phone case in both temperatures. I know another student also didn't find a lot of growth from their phone. Like you, I predicted that many colonies would arise from the phone sample for the simple reason that I, and most people, don't wash our phones very often (oops).
It still makes sense to me intuitively that phones would have many bacteria, but the results seem to disagree with that assumption. Do you think that maybe the difference in results could have to do with the part of the cell phone sampled? I sampled the front of my phone because I thought it was harboring the most bacteria. What about you?
Amy