Mystery TSA dish by Jade

These are the before and after pictures of my TSA plate at 24 degrees Celcius and 37 degrees Celcius. The before picture was taken on the 4th of April and the after picture was taken after three days on the 6th of April. I was curious about the amount and number of bacterial colonies I would find on the table surface, the surface of my phone, my underarms (I know it is disgusting but we all know we have tonnes of bacteria making a nice home down there.) as well as the palm of my hand and that is why I chose to swab these four places.
I divided my plate into four sections.
These were the samples I had on each of the sections.

1: Surface of the phone
2: Surface of the table
3: The dreaded underarms
4: Palm

Figure 1: Picture of TSA plates (incubated at 24 degrees Celcius and 37 degrees Celcius) taken on the 4th of April.

Figure 2: Picture of TSA plates (incubated at 24 degrees Celcius and 37 degrees Celcius) taken on the 6th of April.

After three days, there was no evidence of any bacterial growth on the TSA plate that was incubated at 24 degrees Celcius. However, there was some bacterial growth on the TSA plate that was incubated at 37 degrees Celcius. The first thing I looked at was the third section because I am sure everyone is curious to know what is lurking in those dark pits that we all have.

For the first section there were around 4 colonies of bacteria. The second section had only 1 colony of bacteria and the fourth section had only 5 colonies of bacteria. Surprise, surprise the underarm section which was the third section had approximately a whopping 300 hundred bacterial colonies on it. Looks like a lot of bacteria made a nice cozy nest under my arms. The colonies on section 1, 2 and 4 seem to be the same kind of bacterial colony because they are the same color. However, it seems that the bacterial colony on the 3rd section was different from the rest. My lab partner also did not observe any growth on the TSA plate that was incubated at 24 degrees Celcius. 

To be honest, I was expecting more bacterial colonies to grow on the first section (surface of the phone) because I bring my phone everywhere. I bring it to the bathroom, to restaurants, to the library, to class, on the bus and the list just goes on. My phone is attached to my side 24/7 so I was expecting a lot of bacteria to be on the surface of it but to my surprise there wasn't.
This is what my plates looked like after a week of incubating.

Figure 3: TSA plates after a week of incubation. On the left side is the plate incubated at 24 degrees Celcius and on the right, the plate incubated at 37 degrees Celcius.

After a week, I can clearly see that the colonies on all four sections were different. However, all the colonies were raised and circular. In addition, I had some bacterial growth on the TSA plate that I incubated at 24 degrees Celcius. I also had more bacteria colonies grow on the plate that was incubated at 37 degrees Celcius.

On the first section of the plate I incubated at 37 degrees Celcius were 4 colonies (2 colonies were milky white and the other 2 colonies were yellow). There was 1 white colony on the 2nd section and 9 colonies on the 4th section (7 yellow colonies and 2 orange colonies). There was around 400 colonies on the third section (there were 3 yellow colonies and the rest were white).

There was 5 colonies (2 yellow colonies and 3 white colonies) on the first section of the plate I incubated at 24 degrees Celcius. There was still no colonies on the 2nd section of the plate. There was 12 colonies (1 orange and 1 white colony and 10 yellow colonies) on the 3rd section and 17 colonies (5 orange colonies and 12 yellow colonies) on the 4th section.

From my results, I obtained the same type of bacterial colonies for both my plates in my first section. However, it seems that the bacterial colony on the second section grows better at 37 degrees Celcius compared with 24 degrees Celcius, since it did not appear to grow on the room temperature plate. For the 3rd section, an orange bacterial colony grew on the plate that was incubated at 24 degrees Celcius but not on the other plate. The fourth section had the same bacterial colonies grow on it. In addition, it seems like the white colonies on the 3rd section grows better at 37 degrees Celcius than at 24 degrees Celcius because there were more white bacterial colonies present at 37 degrees Celcius than at 24 degrees Celcius.

I did not expect this experiment to gross me out but it did because I could see with my own two eyes the amount of bacteria lurking in my underarms. There was some bacterial growth on the surface of my phone, my palm as well as the surface of the table but it seems like the table is cleaner than my own body because there was lesser bacteria on the surface of the table in comparison with my own underarms! That shows that the underarm is a perfect place for bacteria to grow and flourish since it provides them with a moist environment.