lab final (medias)

Question 1

what is the purpose of a MAC plate?

Answer 1

differentiate lactose-fermenting and lactose non-fermenting gram-negative cells

Question 2

what are the selective agents in a MAC plate and what do they do

Answer 2

crystal violet and bile salts

select for gram-negative and enteric bacteria

Question 3

what are the differential agents in MAC plate and what do they do

Answer 3

lactose and neutral red

lactose is fermented which results in acidic pH and neutral red to turn a bright pink-red color

Question 4

what is the pH indicator in a MAC plate

Answer 4

neutral red

Question 5

what is the purpose of an MSA plate

Answer 5

to determine if the bacteria is halophilic (salt loving) and if the bacteria can ferment mannitol

Question 6

what does halophilic mean

Answer 6

able to grow in high salt environment

Question 7

what is the purpose of blood agar plate

Answer 7

identify hemolysis

Question 8

blood agar plate has __ media

Answer 8

enriched

Question 9

what is hemolysis

Answer 9

breakdown of red blood cells

Question 10

what is the purpose of sabarouds dextrose agar

Answer 10

grow fungi

Question 11

what is the selective agent in MSA plate and what does it select for

Answer 11

salt

gram + staphylococcos

Question 12

what are the differential agents in MSA plate and what do they differentiate

Answer 12

mannitol - fermentation of acids

phenol red - ph indicator

Question 13

what is the purpose of the simmons citrate test

Answer 13

identify the microbe’s ability to use citrate as an energy source

Question 14

which test uses bromothymol blue

Answer 14

sodium citrate

Question 15

what is the purpose of sim test

Answer 15

test ability of organism to reduce sulfur, produce indole, and motility

Question 16

what is the selective ingredient in the indole test

Answer 16

kovac’s reagent

Question 17

what does kovac’s reagent do in indole test test

Answer 17

identifies production of indole

reacts with indole to produce a red compound

Question 18

what is the purpose of mrvp test

Answer 18

determine which fermentation pathway is used to utilize glucose

Question 19

what are the products of mrvp test

Answer 19

mixed acids or alcohol

Question 20

what is the pH indicator in mrvp test and what does it do

Answer 20

methyl red

indicates if pH is below 4.4 which indicates glucose fermentation and acid production

Question 21

what is the purpose of mueller hinton agar

Answer 21

used in the kirby-bauer method to determine antibiotic resistance

Question 22

which test is used in the kirby bauer method

Answer 22

muller hinton

Question 23

what is the purpose of catalase test

Answer 23

determine presence of catalase

Question 24

how do you interpret the results of catalase test

Answer 24

hydrogen peroxide is added

in a positive reaction, catalase breaks down hydrogen peroxide and causes bubbles

Question 25

what is the broth dilutions test used for

Answer 25

determine MIC (minimum inhibitory concentration) and MBC (minimal bactericidal concentration) of an antimicrobial drug

Question 25

what are negative and positive results for mrvp test

Answer 25

negative - yellow | positive - red

Question 25

what are negative and positive results for citrate test

Answer 25

negative - green | positive - growth or blue

Question 26

in the sim test, what is a positive and negative reaction for sulfur reduction

Answer 26

positive - black | negative - no color change

Question 27

what does a positive and negative result on a MAC plate look like

Answer 27

positive - bright pink | negative - yellow

Question 28

what does a positive and negative result look like on a MSA plate

Answer 28

positive - yellow | negative - pink

Question 29

what do results look like for lactose broth test

Answer 29

positive - yellow | negative - pink

Question 30

how do staph aureus and strep aureus react to catalase

Answer 30

staph: catalase positive strep: catalase negative

Question 31

s aureus and s pyogenes produce what type of hemolysis

Answer 31

Beta hemolysis

Question 32

what is the selective ingredient in SDA and what does it do

Answer 32

antibiotics - grow fungi

Question 33

what is a positive result for motility test

Answer 33

moved away from the stab line

Question 34

what is a positive result for indole test

Answer 34

pink

Question 35

what is added to the mrvp test to indicate glucose fermentation and alcohol production

Answer 35

koh+

Question 36

what is the purpose of lactose broth

Answer 36

identify lactose fermentation and acid production

Question 37

what is the ph indicator in lactose broth

Answer 37

phenol red

Question 38

what is a positive result of lactose broth

Answer 38

yellow and gas bubble in durham tube

Question 39

which test uses a durham tube for gas collection

Answer 39

lactose broth

Question 40

s pyogenes is catalase positive or negative

Answer 40

catalase negative