MEDIA

Question 1

What is the primary purpose of blood agar?

Answer 1

Isolation of non-fastidious microorganisms & determine hemolytic reactions.

Question 2

What is the primary purpose of MacConkey agar?

Answer 2

Select for gram negative organisms and differentiate between lactose and non lactose fermenters.

Question 3

What are the main ingredients in blood agar?

Answer 3

-Peptone
- Sodium chloride
- agar
- 5% Sheep blood

Question 4

What are the main ingredients in MacConkey Agar?

Answer 4

• Crystal violet
• neutral red
• bile salts
• peptone base
• lactose

Question 5

Which ingredients in MacConkey agar make it selective?

Answer 5

Crystal Violet & Bile salts

Question 6

Which ingredients in MacConkey agar make it differential?

Answer 6

Neutral red & lactose

Question 7

What is the primary purpose of chocolate agar?

Answer 7

Growth of fastidious bacteria.

Question 8

What are the main ingredients in chocolate agar?

Answer 8

-peptone base
- sodium chloride
- Hgb

Question 9

What ingredients in Chocolate agar make it enriched?

Answer 9

RBC are lysed when agar base is heated lysing the cells releasing X (hemin) and V (NAD) factors.

Question 10

What is the primary purpose of CNA agar?

Answer 10

Selective for isolation of gram positive organism.

Question 11

What are the main ingredients of CNA?

Answer 11

• Colistin
• Nalidixic acid
• 5% sheep blood

Question 12

What ingredients in CNA make it selective?

Answer 12

Colistin and Nalidixic acid prevent growth of Gram negative organisms.

Question 13

What is the primary purpose of PEA agar?

Answer 13

Selective for the isolation of aerobic GP, GPC and GNB organisms

Question 14

What ingredients make PEA selective?

Answer 14

Phenylethyl alcohol inhibits GN

Question 14

What are the main ingredients of PEA?

Answer 14

• Nutrient agar base
• phenylethyl alcohol
• 5% sheep blood

Question 15

What is the primary purpose of Mannitol Agar?

Answer 15

Selective for Staph, differentiates between coag + staph and non pathogenic staph.

Question 16

What are the main ingredients of Mannitol Agar?

Answer 16

• peptone base
• mannitol
• phenol red
• 7.5% NaCl

Question 17

What ingredients in Mannitol Agar make it selective?

Answer 17

7.5% NaCl - as high salt concentration inhibits most growth except for Halotolerant organisms

Question 18

What ingredients in Mannitol Agar make it differential?

Answer 18

Phenol red & Mannitol

Question 19

What is the primary purpose of Mueller Hinton Agar?

Answer 19

Used for AST

Question 20

What are the main ingredients in Mueller Hinton agar?

Answer 20

-Beef extract
- Casein
- Starch
- Agar

Question 21

What is the main purpose of Brain Heart Infusion agar?

Answer 21

Cultivation of fastidious organisms

Question 22

What are the main ingredient s of brain heat infusion media?

Answer 22

• Dextrose
• Pork brain
• Heart infusion
• peptone
• sodium chloride
• disodium phosphate

Question 23

What is the primary purpose of Sabouraud agar?

Answer 23

Selective for yeast and filamentous fungi

Question 24

What are the primary ingredients in Sabouraud agar?

Answer 24

- Myocological peptones - dextrose - agar - antibiotics

Question 25

What is the purpose of Loeffler medium?

Answer 25

Isolation and growth of Corynebacterium

Question 25

What is the primary purpose of Tinsdale agar?

Answer 25

Selective and differentiates C.diphtheriae from other corynebacterium spp.

Question 26

What is the tell all sign that a tinsdale agar has growht of C.diptheria?

Answer 26

Black colonies with Brown halos

Question 27

What ingredient in tinsdale agar is differential?

Answer 27

Reduction of Potassium tellurite

Question 28

What is the primary purpose of Thayer-Martin agar?

Answer 28

selective for N.gonorrhoeae and N.menigitidis

Question 29

What are the primary ingredients in Thayer-Martin agar?

Answer 29

- Blood agar base - Hgb and supplement B

Question 30

What is the primary purpose of Modified Thayer Martin?

Answer 30

Selective for brucella spp.

Question 31

what ingredient in Modified-TM differentiate it from TM agar?

Answer 31

- Colistin - Nystatin - Vanc - Trimethoprim

Question 32

What is the purpose of thioglycollate broth?

Answer 32

Used for the recovery of anaerobes

Question 33

What are the main ingredients in thio broth?

Answer 33

- Pancreatic digest of casein - soy broth - glucose - thioglycollate - agar

Question 34

what is the purpose of HEK agar?

Answer 34

Isolation of salmonella & shigella from stool

Question 35

What are the main ingredients in HEK agar?

Answer 35

- Peptone with bile salts - lactose -sucrose - salicin - ferric ammonium citrate - bromothymol blue - acid fuchsin

Question 36

What ingredients in HEK make it selective?

Answer 36

Peptone base and bile salts

Question 37

what ingredients in HEK make it differential?

Answer 37

- lactose -sucrose - salicin - ferric ammonium citrate - bromothymol blue - acid fuchsin

Question 38

What is the purpose of MacConkey Sorbitol agar?

Answer 38

Isolation and differentiation of E.coli O157:H7

Question 39

What are the main ingredients in MacConkey Sorbitol agar?

Answer 39

- Crystal Violet - neutral red - bile salts - Peptone base - D-sorbitol

Question 40

What ingredients in SMAC make it selective?

Answer 40

Bile salts and crystal violet

Question 41

What ingredient in SMAC make it differential?

Answer 41

sorbitol and neutral red

Question 42

What is the purpose of Salmonella Shigella agar?

Answer 42

Selective for salmonella and shigella

Question 43

What are the main ingredients in Salmonella-Shigella agar?

Answer 43

- Peptone base w Lactose - ferric ammonium citrate - sodium thiosulfate - neutral red - brilliant green -bile salts

Question 44

What ingredients in Salmonella-shigella agar make it selective?

Answer 44

Brilliant green and bile salts inhibit coliforms

Question 45

What ingredients in Salmonella-shigella agar make it differential?

Answer 45

Ferric ammonium citrate, sodium thiosulfate, neutral red

Question 46

What is the purpose of selenite broth?

Answer 46

Isolation of low numbers of salmonella

Question 47

What is the purpose of XLD media?

Answer 47

Selective and differential for Salmonella and shigella

Question 48

What are the main ingredients in XLD agar?

Answer 48

- Yeast extract - lysine - xylose - lactose - sucrose - bile salts - ferric ammonium citrate - sodium deoxycholate - phenol red

Question 49

What ingredients in XLD media make it selective?

Answer 49

Bile salts,

Question 50

What ingredients in XLD media make it differential?

Answer 50

- Lysine, xylose, lactose, sucrose - ferric ammonium citrate - sodium deoxycholate - phenol red

Question 51

What is the purpose of Campylobacter agar?

Answer 51

Isolation of Campylobacter species.

Question 52

What are the main ingredients in campy agar?

Answer 52

- peptones - yeast extract - Burcella agar base -Vancomycin - Trimethoprim - Polymyxin B / colistin -

Question 53

What is an additional ingredient found in CCDA and Karmali campy agar?

Answer 53

Charcoal to neutralize toxic oxygen radicals and metabolic byproducts.

Question 54

What is the purpose of CIN plate?

Answer 54

selective for Yersinia, and my be used for the isolation of Aeromonas.

Question 55

What are the main ingredients in CIN plate?

Answer 55

- Peptone with Yeast - Mannitol - Bile salts - Neutral red - crystal violet - cefsulodin, irgasan and novobiocin

Question 56

What colonial morphology will yersinia have on CIN agar?

Answer 56

Bullseye appearance