Mystery Bacteria on TSA agar plates by Robert Barker

Day 0

            I started out wondering what organisms were on my wheelchair. I like keeping myself healthy so, I also decided to make sure my tattoo on my shoulder was not covered with unnecessary bacteria. I also took a sample from my tongue. The last item I took a sample of was the telephone in the lab. I made two plates; each of them contained the same samples. One of the plates was left out in room temperature, whereas; the other sample was put into an incubator of 37̊̊ Celsius (body temperature). I hypothesized that the organisms on my wheelchair  would be of great abundance in the body temperature incubator. I  thought that if you took the organisms out of their normal habitat, room temp. or body temp., that they would speed up production. I unfortunately did not take a picture the first day.

Day 2

Figure 1: Plates growth after 2 days of incubation. The left plate was placed at 37 degrees Celsius and the right was in room temperature incubation.

            I entered class and checked up on how the bacteria was growing. I was surprised at the results I obtained. My hypothesis was beginning to be supported but, not as quickly as I thought it would be. My tongue was the only item not supported in my hypothesis. After two days there was no growth on my room temperature plate that I could see. The plate incubated at body temperature had some growth but, the room temperature one did not.

Colonies on body temperature:

Tongue - 2

Wheelchair tire  ̴ 16

Tattoo on shoulder  ̴̴  13

Phone in lab  ̴ 1

Day 7

Figure 2: Plates growth after 7 days. The plate on the left is TSA agar plate that was incubated at body temperature. The plate on the right is incubated at room temperature.

       My hypothesis on why no bacteria grew on the room temperature samples of my tongue, shoulder and on the school phone is because I may have not actually swab the surface before rubbing the q-tip on that plate. 

Colonies on TSA agar Plates

         Room temperature plate                                    Body temperature plate

                                                                                         Tongue  ̴ 4

            Wheelchair is approximately 600 colonies                                                                                                                                                                        Wheelchair Tire  ̴  29 

                                                                                           (based on Figure three)

                                                                                            Tattoo on Shoulder  ̴ 16

                                                                                             Phone in lab  ̴  6 

Closer Image of Wheelchair tire

Figure 3: Image of my wheelchair tire under the dissecting microscope after 7 days of Body temperature environment.

 I was intrigued by all the growth on the wheelchair tire incubated at body temperature. The organism at bottom right, the whitish grey one, looked like cauliflower to me. When looking at the Medical Microbe Gallery ¹, I believe I can conclude that the organism is a Nocardia asteroides morphology. I also see Staphylococcus aureus morphology.

Reference used:

1. http://www.microbelibrary.org/component/resource/laboratory-test/3114-colony-morphology?limit=0&limitstart=0