Day 0
I wanted to check the amounts of bacteria present on common areas, on myself and around me, so I decided to go with my a spot on my forearm, the sole of my shoe, my mouth, as well as the desk which the handwashing sink is installed. It's also worth noting that the desk is next to an aquarium. I hypothesized that either my shoe or desk will have the highest volume of bacteria, and that my mouth possesses more germs than my arm because I shower almost daily.
Day 2
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| Petri dish incubated at room temperature during day 2. |
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| Petri dish incubated at 37 degrees celsius during day 2. |
During day 2, I found that my mouth held the highest volume of bacteria which isn't too surprising considering all the food I eat and I actually need a lot of bacteria to break down the food, but while my mouth had the biggest colony, the sole of my shoe and the desk exhibited the biggest sized bacterias. Unsurprisingly, my arm had the least amount of bacterial growth. In addition, the petri dish incubated at 37 degrees celsius showed significantly more growth. Actually, the petri dish incubated at room temperature showed very little growth.
I am unsure of exactly what kind of bacteria was in my mouth besides for being some kind of coccus, but I believe to have found either Mycobacterium smegmatis or Bacillus subtilis on the sole of my shoe and the desk, and I probably found Staphylococcus aureus on the two aforementioned areas and on my arm.
Day 7
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| Petri dish incubated at room temperature during day 7. |
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| Petri dish incubated at 37 degrees celsius during day 7. |
Besides for the mouth portion of the 37-degree petri dish, all the areas on both dishes exhibited substantial bacterial growth. This time around, the sole of my shoe yielded the highest apparently volume of growth. There appeared to be:
- on the dish incubated at room temperature: about 16 colonies of Staphylococcus aureus from my arm, about 12 colonies of what I think is Staphylococcus aureus from the desk, and about 30-40 colonies the same bacteria from my mouth and the sole of my shoe, although there are some unknown isolate morphology in there as well.
- on the dish incubated at 37 degrees celsius: 6 huge colonies of Mycobacterium smegmatis from the desk, 23 colonies of Staphylococcus aureus from my arm, a myriad of Staphylococcus aureus and unknown isolate morphology from my shoe, and a myriad of some kind of coccus from my mouth.
My hypothesis seems to be right in the end, my shoe and the desk with the handwashing sink turned out to be the dirtiest of the objects I sampled.
Hi Kevin, it was interesting to see from looking at other samples containing shoes just how much bacteria actually forms there. After looking at the huge amount of growth on the shoe sample, might reconsider picking food off the ground in which shoes might have passed through. Another interesting thing to note is that on Day 7, it seems from your picture to have more growth on the Room Temperature sample than the 37C sample, this might indicate that more bacteria thrive on normal room temperature environment on your shoes than in warm conditions. There also is a large range of bacteria from the large blobs from the shoes to the tiny speck in your mouth, just goes to show how ubiquitous bacteria really is!
ReplyDeleteI found the size difference interesting as well. Yes Thomas never pick up food off the floor and eat it. I read an article where it only takes like 2 seconds for bacteria to get on food that is on the floor. Also, I tried to look up the mouth bacteria and it looks alot like Staphylococcus epidermidis which is found ubiquitously on healthy human skin and mucosal surfaces. I could be wrong but while looking this up I realized just how much bacteria is essential for our biological function.
ReplyDeleteHi Kevin,
ReplyDeleteYou had some really cool looking bacteria growing on your TSA plates. The bacteria from your shoe looks disgustingly interesting. I also did a sample from my mouth, and it looked almost identical to the growth on your plate although my room temperature plate had more growth than in body temperature. The bacteria from your shoes looks really cool! I'm curious to see what kind of bacteria makes up all those colonies in there. Like Thomas mentioned, I think it would be cool to take samples from things that were left on the ground and stepped on. I'm sure there would be all kinds of bacteria from those results. Great post!