Microbiology Lab Exam 3

Question 1

Staphylococcus Epidermis

Answer 1

gram positive cocci in irregular clusters.
(staphylococci: cocci grouping in clusters)

Question 2

E.coli

Answer 2

gram negative, rod-shaped. form clusters
(staphylobacilli: bacilli grouping in clusters)

Question 3

S. marcescens

Answer 3

gram negative, rod-shaped (bacillus)
(staphylobacilli?: bacilli grouping in clusters) or single?

Question 4

bacillus subtilis

Answer 4

gram positive, rod shaped (bacillus)
(streptobacilli: bacilli grouping in chains)

Question 5

micrococcus luteus

Answer 5

gram positive cocci, in pairs and tetrads

Question 6

staphylococcus aureus

Answer 6

gram positive
cell shape: coccus
cell grouping: staphylo

(coccus in clusters)

Question 7

streptococcus pyogenes

Answer 7

gram positive
cell shape: coccus
cell grouping: strepto

(coccus in chains)

Question 8

bacillus anthracis

Answer 8

gram positive
cell shape: bacillus
cell grouping: strepto

(bacillus in chains)

Question 9

aqua spirillum serpens

Answer 9

gram negative
cell shape: spiral
cell grouping:single

Question 10

mycoplasma pneumonia (acid fast) (not part of the gram stain, it’s separate)

Answer 10

acid fast because it tested pink (mycobacterium is present)
cell shape: bacillus
cell grouping: single