Tests

Question 1

BAP Agar

Answer 1

Blood
alpha hemolysis - green and partially hydrolysed
beta hemolysis - clear/yellow and comple hydrolysis
gamma hemolysis - none

Question 2

MSA Agar

Answer 2

Mannitol salt (10%) inhibits all except staph spp.
Mannitol - fermented by staph, color change red to yellow

Question 3

MacConkey

Answer 3

Selective and Differential: dyes inhibit gram pos, contains lactose so fermented changes to purple

Question 4

Hektoen Agar

Answer 4

Contains lactose, thiosulfate, ferrous sulfate and green dye
If bact prod H2S, non lactose = green with black center
Salmonella spp.

Question 5

ENT Agar

Answer 5

Contains bile (inhibs gram pos staph) and sodium azide (inhibs gram pos). Contains esculin and peptone as nutrients and ferric citrate as indicator.
Colonies are dark and spread
Enterococcus faecalis

Question 6

MYC and SAB

Answer 6

Selective for fungi, acidic and anti-bact

Question 7

Catalase

Answer 7

Tests if organism can detox some immune chems. (H202 to water)

Question 8

Coagulase

Answer 8

interacts with prothrombin to clot

Staph aureus

Question 9

Oxidase test

Answer 9

measures cytochrome oxidase presence. Pos = purple

Pseudomonas aeruginosa

Question 10

Bile solubility test

Answer 10

if sensitive - clear liquid
strep pneumonia - sensitive
strep mitis - insensitive

Question 11

Urease test

Answer 11

pink/red = pos; yellow = neg

Proteus spp and H. Pylori

Question 12

Indole Test

Answer 12

Pos = red (dipstick=blue)

E. Coli

Question 13

Sensitivity test

Answer 13

Optochin - strep pneu
Novobiocin - staph sapr
Bacitrian - strep pyogenes

Question 14

PYR Test

Answer 14

Activity of pyrolidonyl arylamidase detected
Pos=pink
Group A strep (pyogenic), Group D Enterococci (Enterococcus spp), coag neg staph spp