Classification

Question 0

How can you further subdivide glucose fermenters?

Answer 0

Oxidase positive and negative

Question 1

What are the two subdivisions of gram negative rods?

Answer 1

Glucose fermenters and non- fermenters

Question 2

What are the two types of oxidase negative bacteria?

Answer 2

Enteric and non- enteric

Question 3

What do glucose fermenters release?

Answer 3

CO2 and H2O

Question 4

Give examples of typical enterobacteria

Answer 4

Salmonella, E.Coli

Question 5

Classify enterobacteria

Answer 5

Enteric, oxidase negative, glucose fermenting, gram -ve rods

Question 6

What do typical enterobacteria colonies look like on agar?

Answer 6

Large, grey, translucent

Question 7

Common name for enterobacteria

Answer 7

Coliforms

Question 8

What is MacConkey’s medium?

Answer 8

Medium containing bile salts so only certain organisms grow- gut enterobacteria

Question 9

How can you further divide enterobacteria?

Answer 9

Lactose fermenters and non-fermenters

Question 10

Are traditionally harmless bacteria of gut lactose fermenters or non-fermenters?

Answer 10

Fermenters

Question 11

Do traditional gut pathogens (shigella, salmonella) ferment lactose?

Answer 11

No

Question 12

What colour do colonies of lactose fermenters look on agar and why?

Answer 12

Pink- produce acid - neutral red dye (e. coli)

Question 13

What colour do non- lactose fermenter colonies look?

Answer 13

Yellow/colourless

Question 14

Why can E.Coli be used as a measure of faecal contamination?

Answer 14

Only comes from colon