Lab Final

Question 1

Mannitol Salt Agar

Answer 1

selective : Halodures (high salt)
Differential: Manitol Fermentation (sugar) (Color change red→yellow)

Question 2

MacConkey Agar

Answer 2

Selective: Gram-negative (bile)
Differential: Lactose Fermentation (lactic acid) (color change purple→magenta/red = pH drop)

Question 3

Starch

Answer 3

Differential: Starch hydrolysis (breaking sugar bond) (starch + iodine= blue/purple)

Question 4

TSA

Answer 4

Complex media
Test: oxidase (blue color=positive)

Question 5

Blood agar

Answer 5

Differential Media
Green Hemolysis = Alpha (Incomplete)
Clear Hemolysis = Beta (Complete)
Red Hemolysis = Gama (None)

Question 6

Catalase Test

Answer 6

Test for the presence of Enzyme: catalase

Question 7

Handwashing Lab

Answer 7

Handwashing = 80% infections passed
Nose = 30% infections passed (mannitol salt agar)
Throat= 10-20% infections passed (blood agar)

Question 8

Group A Beta Hemolysis

Answer 8

Streptococcus Pyogenes

Question 9

counts viable organisms

Answer 9

all organisms present in the sample

Question 10

Water

Answer 10

Coliforms

Question 11

Dilution

Answer 11

CFU/g or mL sample = number of colonies/quantity plated x Dilution
EX: 129 colonies counted on a 10^3 dilution 129=129/1mL x 10^3cfu/g =129,000 cfu/g

Question 12

Antibiotic Susceptibility: Kirby Bauer Test (STATIC)

Answer 12

Allows the agent to diffuse freely into the agar
Mueller Hinton agar
Disk diffusion method

Question 13

Disinfect Susceptibility: TSA wells

Answer 13

STATIC TEST (inhibits growth)
ZOI (zone of inhibition)

Question 14

Antiseptic Activity:

Answer 14

CIDAL Test

Question 15

Fermentation

Answer 15

Occurs with little to no oxygen
Purpose=NAD

Question 16

Glycolysis

Answer 16

GLUCOSE → PYRUVIC ACID = Glycolysis
NAD+ → NADH
2 ADP → 2 ATP

Question 17

Fermentation

Answer 17

PYRUVATE → LACTIC ACID (waste) = Fermentation
NADH → NAD+
PYRUVATE → CO2

Question 18

RODACS

Answer 18

Replicate Organism Detection and Counting