Lab 14: Isolation of Microbes from the Human Body

Question 1

What two places of the body were microbes isolated from?

Answer 1

1) The skin (behind the ear)
2) The oral cavity (back of the throat)

Question 2

What plates were inoculated with the oral cavity swab?

Answer 2

1) TSA
2) BA
3) MSA

Question 3

What plates were inoculated for the skin (behind ear) swab?

Answer 3

1) TSA
2) MSA
3) SDA

Question 4

Why was the SDA plate used for the skin sample?

Answer 4

To isolate any yeast growing on skin

Question 5

Name 2 types of bacteria that typically colonize the skin (exterior)

Answer 5

1) Micrococcus
2) Staphylococcus (aureus and epidermidis)

Question 6

Name the 3 typical mucosal (mouth) colonizers

Answer 6

1) Staph aureus
2) Streptococci
3) Enterococcus
4) Corynebacterium

Question 7

Where are bacteria typically abundant in the oral cavity?

Answer 7

Underneath the gums

Question 8

1) What are the yellow bacteria typically isolated from the skin?
2) What are the white bacteria isolated from the skin?

Answer 8

1) Micrococcus: Yellow
2) S. epidermidis and S. aureus: White

Question 9

Name the 3 bacteria typically seen in the mouth

Answer 9

1) Streptococci (tiny colonies)
2) Haemophilus
3) Cyanobacterium

Question 10

What does clearing on a plate of isolated mouth bacteria indicate?

Answer 10

Beta hemolysis, which means it’s more likely a pathogen

Question 11

1) What commensal microbes live on the skin?
2) What commensal microbes live in the mouth?

Answer 11

1) Staphylococcus, Micrococcus, Corynebacterium, Pityrosporum (yeast)
2) Staphylococcus, Micrococcus, Streptococcus

Question 12

Name 5 potential pathogens

Answer 12

1) S. aureus
2) St. pyogenes
3) Neisseria
4) Haemophilus
5) S. epidermidis