Identification Procedures

Question 1

Motility Tests

Answer 1

Wet prep

Hanging drop

Question 2

How do you prep a wet prep?

Answer 2

A moderately heavy suspension of bacteria is made in a few mls of nutrient broth and incubated for 2-3 hours.
Place a loopful of culture on a slide and examine on high dry objective lens

Question 3

What are you looking for on a wet prep

Answer 3

Bacterial motility vs Brownian movement

Question 4

Brownian movement

Answer 4

The random motion of a particle as a result of collisions with surrounding gaseous molecules

Question 5

Hanging Drop

Answer 5

A drop of liquid suspended from a cover glass usually placed over the cavity of a depression slide and containing microorangisms or cells

Question 6

What is so special about the slides that are being used?

Answer 6

They have a concave area that allows the liquid to suspend in order to view motility

Question 7

What does the motility media allow?

Answer 7

The motile bacteria to diffuse out into the medium for detection of motility of bacteria

Question 8

How do you do a motility test?

Answer 8

First tube is incubated at 37 degrees celsius

Second tube is incubated at room temperature

Question 9

What does non-motile bacteria look like after the tests?

Answer 9

Growth is restricted to the stab inoculation line

Question 10

What does motile bacteria look like after the test?

Answer 10

Diffuse growth throughout the medium

Question 11

When do you use a motile test?

Answer 11

If organisms are nonmotile on microscopic examination

Question 12

Catalase Test

Answer 12

Used to determine whether a gram-positive cocci is a staphylococci or streptococci

Question 13

Positive Catalase Test

Answer 13

Bubbles after adding 3% hydrogen peroxide to slide

Question 14

What bacteria comes up positive on a Catalase Test?

Answer 14

Staphylococci

Question 15

Negative Catalase Test

Answer 15

No bubbles

Question 16

What bacteria come up on a negative catalase test

Answer 16

Streptococci

Question 17

Coagulase Test

Answer 17

Differentiates coagulase positive Staph and coagulase negative Staph

Question 18

What are coagulase positive bacteria

Answer 18

Staphylococcus aureus

Staphylococcus pseudointermedius

Question 19

What are coagulase negative bacteria

Answer 19

Staphylococcus epidermidis

Staphylococcus saprophyticus

Question 20

Slide coagulase

Answer 20

Detects surface bound coagulase or clumping factor

Question 21

What does a positive tube coagulase look like

Answer 21

A clot formation

Question 22

What bacteria comes up positive on a tube coagulase test?

Answer 22

Staphylococcus aureus

Question 23

Which enzyme coagulates plasma

Answer 23

Coagulase

Question 24

Oxidase Activity

Answer 24

The oxidase test identifies organisms that produce the enzyme cytochrome oxidase

Question 25

What bacteria does the Oxidase activity test differentiate

Answer 25

Escherichia coli vs Pseudomonas aeruginosa

Question 26

What does a positive oxidase test look like?

Answer 26

Microorganisms are oxidase positive when the color changes within 15 to 30 seconds

Question 27

What bacteria does a positive oxidase test indicate?

Answer 27

Pseudomonas aeuriginosa

Question 28

What does a negative oxidase activity test indicate?

Answer 28

Escherichia coli | No color change

Question 29

For the oxidase activity test, what must be present in the bacteria?

Answer 29

Cytochrome Oxidase enzyme

Question 30

Why would you get a false positive oxidase activity test?

Answer 30

Because you did not use oxidase reagent that was still clear, or you read your test too quickly once you had performed it

Question 31

Gram positive cocci | Catalase negative

Answer 31

Streptococcus spp

Question 32

Staphylococcus epidermidis

Answer 32

Gram positive cocci Catalase positive Coagulase negative

Question 33

"Golden staph" Gram positive cocci Catalase positive Coagulase positive

Answer 33

Staphylococcus aureus

Question 34

Gram negative bacilli | Oxidase positive

Answer 34

Pseudomonas aeruginosa

Question 35

Gram negative bacilli | Oxidase negative'

Answer 35

Escherichia coli

Question 36

Acid Production for Glucose

Answer 36

For fastidious organisms

Question 37

California Mastitis Test

Answer 37

Helps confirm the presence of subclinical mastitis | Uses milk, a reagent, and a paddle

Question 38

What are the most common organisms found in the milk?

Answer 38

``` S. aureus Streptococcus agalactiae Streptococcus uberis E. coli Corynebacterium spp Pseudomonas aeruginosa ```