(Lab 2) Organisms to Know

Question 1

What are the properties of Enterobacteriaceae?

Answer 1

• G- bacilli
• oxidase-negative
• glucose fermenting

Question 2

What is the result of E. coli in selective and differential media?

Answer 2

PEA: negative. no growth
MSA: Negative, weak growth (non-halophile)
EMB: Metallic green, strong growth: G- (lactose fermenter)

Question 3

What is the result of S. aureus in selective and differential media?

Answer 3

PEA: Pos. Strong growth
MSA: Pos. Yellow color (halophile, mannitol fermenter)
EMB: Weak growth G+ (non-lactose fermenter)

Question 4

What is B. cereus result in diestive exoenzymes?

Answer 4

Starch agar: positive
milk agar: positive

Question 5

What is Corynebacterium xerosis O2 requirement?

Answer 5

Obligate aerobe

Question 6

What is M. luteus O2 requirement?

Answer 6

Microaerophile

Question 7

What is M. morganii O2 requirement?

Answer 7

Facultative anaerobe

Question 8

What is Clostridium sporogenes O2 requirement?

Answer 8

Obligate anaerobe

Question 9

What were all the members of Enterobacteriaceae in the carbohydrate fermentation test?

Answer 9

E. coli, Enterobacter aerogenes, and Providencia stuartii

All break down glucose into acids

Question 10

What was Proteus vulgaris’ result in urease test?

Answer 10

Positive