Question

E. coli is an intestinal organism, and Staphylococcus epidermidis resides on the skin. What do you hypothesize will occur when both are inoculated onto mannitol salt agar

Answer 1

The options

A. Both organisms will grow since they are both ubiquitous of 20.

B. Neither organisms will grow beacause 75% salt inhebits at organisms.

C. The salt inhibits the growth of E.coli which is not a halophyte, but S.epidermidis grows.

D. The S epidernidis will not grow since it must exist at as a pure cuture the E.coli will grow."

The CORRECT ANSWER IS C.

C. The salt inhibits the growth of E.coli which is not a halophyte, but S.epidermidis grows.

Step-by-step explanation:

Mannitol Salt Agar is known for its highly selective property. This explains why it is mostly used for isolation of Staphylococcus which ferments mannitol (for nutrient-carbohydrate). Staphylococcus unlike any other bacteria such as (E. Coli etc.) is resistant to sodium chloride even at a high concentration amount for the salt.

Answer 2

The options

A. Both organisms will grow since they are both ubiquitous of 20.

B. Neither organisms will grow beacause 75% salt inhebits at organisms.

C. The salt inhibits the growth of E.coli which is not a halophyte, but S.epidermidis grows.

D. The S epidernidis will not grow since it must exist at as a pure cuture the E.coli will grow."

Answer: C.

Agar is characterised by Escherichia coli not growing and Staphylococcus epidermidis growing and observing colorless to pink colonies.

Step-by-step explanation:

This agar a differential medium for mannitol fermentors,

It encourages the growth of a group of certain bacteria while inhibiting the growth of others.

Note: an acidic by product is formed if an organism can ferment mannitol, that will cause the phenol red in the agar to turn yellow.