(Laboratory) Identification of Pseudomonas

Question 1

List down the step-by-step procedure in Gram Staining of Pseudomonas:

Answer 1

1. Prepare a smear from the bacterial source.
2. Air dry and proceed with the staining.
3. Observe microscopic morphology under the microscope.

Question 2

List down the step-by-step procedure in the Nutrient Agar Inoculation of Pseudomonas:

Answer 2

1. Inoculate bacteria from the source plate into the Nutrient agar.
2. Incubate overnight. Observe the colonial morphology.

Question 3

List down the step-by-step procedure in the TSI of Pseudomonas:

Answer 3

1. Sterilize your inoculating needle and pick an isolated colony from your source plate.
2. Observe aseptic techniques. Stab the butt portion of the media and continue making serpentine motion on the slant portion.
3. Incubate overnight. Interpret based on color reaction.

Question 4

List down the step-by-step procedure in the SCA of Pseudomonas:

Answer 4

1. Sterilize your inoculating needle and pick an isolated colony from your source plate. Make sure to get only a small portion of the bacterial growth. Do not take too much.
2. Observe aseptic techniques. Inoculate the surface of the slant with serpentine motion.
3. Incubate overnight.

Question 5

List down the step-by-step procedure in the Oxidase Test of Pseudomonas:

Answer 5

1. Using a sterile loop/applicator stick, rub a colony into the oxidase strip
2. Observe for color change

Question 6

Positive result of the Oxidase Test of Pseudomonas

Answer 6

Purplish to black

Question 7

Negative result of Oxidase Test of Pseudomonas

Answer 7

No color change

Question 8

Is Pseudomonas oxidase positive or oxidase negative?

Answer 8

Oxidase positive

Question 9

Is Pseudomonas catalase positive or negative?

Answer 9

Catalase positive

Question 10

Pseudomonas are catalase positive and oxidase positive except for _____ and _____

Answer 10

Pseudomonas luteolus
Pseudomonas oryzihabitans

Question 11

P. fluorescens and P. putida are differentiated by _____

Answer 11

Gelatin Hydrolysis

Question 12

Gelatin hydrolysis can be used to differentiate the two species from each other; P. putida is _____ and P. fluorescens is _____

Answer 12

Negative
Positive

Question 13

P. fluorescens and P. putida are susceptible to:

Answer 13

Aminoglycosides
Polymyxin
Piperacillin

Question 14

P. fluorescens and P. putida are resistant to:

Answer 14

Carbenicillin
SXT

Question 15

P. aeruginosa is ADH (positive or negative)

Answer 15

ADH Positive

Question 16

P. aeruginosa is Citrate (positive or negative)

Answer 16

Citrate Positive

Question 17

Medium used in the identification of P. aeruginosa

Answer 17

Cetrimide Agar

Question 18

TSI reaction of P. aeruginosa

Answer 18

K/K without gas
H2S Negative

Question 19

P. aeruginosa is resistant to:

Answer 19

• Penicillin
• Ampicillin
• 1st and 2nd generation cephalosporins
• Trimethoprim-sulfamethoxazole
• Chloramphenicol
• Tetracyclines

Question 20

P. aeruginosa is susceptible to:

Answer 20

• Aminoglycosides
• Semisynthetic penicillins
• 3rd and 4th generation cephalosporins
• Carbapenems and fluoroquinolones