Shared Flashcard Set

Details

Lab Exam 2
Lab Practical 2
27
Microbiology
Undergraduate 2
11/04/2011

Additional Microbiology Flashcards

 


 

Cards

Term

1. What is the Gelatin Test looking for?

2. What indicates a positive vs negative test?

3. What microbe demonstrates a positive test?

Definition

1. It is looking for the presence of proteases

2. A positive test = Liquefied Medium Negative = solid medium.

3. Pseudomonas aeruginosa

Term

1. The Phenol Red Broth Test is used to differentiate what?

2. What indicates positive for presence of acid, and negative for presence of acid?

3. What mediums were used with the Phenol Red?

4. Two Examples are?

Definition

1. Phenol Red is a pH indicator and differentiates between  which  

    organisms produce acid vs non-acid and gas vs non-gas by-products  

    of fermentation 

2. Yellow = Acidic Red = No Fermentation taken place Pink = Alkaline due to peptone degradation) Bubble = Gas Present (C02)

3. Lactose, Sucrose, and Glucose

4. Enterococcus faecalis: all 3 yellow tubes with no gas

    E. Coli:  Sucrose > red w/ no gas

               Lactose > yellow w/ gas

               Glucose > yellow w/ gas

Term
1. Starch Agar Plate tests for what?
2. What indicates a positive vs a
negative test?
Definition
1. It tests for the presence of
Amylase via Starch Hydrolysis
2. Iodine is added to the Starch Agar.
If Starch his present, it complexes
with the Iodine and turns dark
brown/black. T
Black = Negative for Amylase
Clearing = Positive for Amylase
Term
1. Milk Agar Plate tests for the presence of what?
2. What indicates a positive vs a negative result?
Definition

1. Tests for the presence of a protease called casease.

2. Positive = clearing / halo in gar

    Negative = no clearing or halo

Term
  1. Spirit Blue Agar test, tests for the presence of what?
  2. What indicates a positive vs negative test?
Definition
  1. Spirit blue tests for the presence of Lipases
  2. Postive = A clearing in the blue agar indicates   Negative = No clearing, all blue.
Term

Which organism is good at all three tests: Spirit Blue Agar, Starch Agar , Milk Agar 

 

Definition
Bacillus
Term
  1. What is a Quadrant Streak? 
  2. What is it's purpose?
  3. What two organisms did we use for this?
Definition
  1. A quadrant streak is when you streak 1 quadrant and then spread it out through all 4 quadrants on a agar plate
  2. To promote and demonstrate greater separation of colonies - look for separation
  3. Serratia and E. Coli
Term
  1. What is the radiant streak? 
  2. What did we use to inoculate?
Definition
  1. A radiant streak is when you streak across one quadrant, and then creat 3 - 4 additional perpendicular linear streaks from the origin streak
  2.  Saliva

 

Term

What does MaConkey Agar test for?

 

What are do the color changes indicate?

Definition

MaConkey Agar tests for Enterics, and separates them into 2 groups - Lactose fermenters and non lactose fermenters.

 

Lactose Fermenters = Pink, red, purple colonies

Non Lactose Fermenter = Tan / Colorless Colonies

 

 

Term
Which organisms are good Lactose Fermenters?
Definition
E. Coli , Enterobacter, Klebsiella
Term
Which organisms are non lactose fermenters?
Definition
Proteus vulgaris, Salmonella, Shigella, Pseudomonas
Term

What does Mannitol Salt Agar Test look for?

 

What are it's indications for positive and negative?

Definition

Mannitol Salt Agar tests for Staphylococcus Aureus specifically.

 

Positive = Yellow colony or halo

Negative = Red or No Growth

 

Term

Triple Sugar Iron Agar (TSI) What does is it test for?

 

What are the active indicators?

 

 

Definition

Designed to differentiate bacteria on the basis of glucose, sucrose, and lactose fermentation and sulfur reduction.

 

Phenol Red is the pH indicator and the Iron in the ferrous sulfate is the Hydrogen Sulfide indicator. 

Term
In a TSI test, what does a red slant and yellow but indicate?
Definition

A red slant and yellow butt indicates that the organism ferments glucose but not lactose. 

 

Inoculated with a glucose only fermenter, acid by-products lower pH and turn medium yellow.

After a few hours since glucose low concentration, it will be exhausted and alakaline reversion takes place, and NH3 production turns the slant more alkaline.

Term

In a TSI test, what does a yellow slant and yellow butt  indicate?

Definition

Acidic slant and butt

 

Yellow Slant and Yellow butt indicates that the organism is able to ferment Glucose and Lactuse and/or Sucrose and turn the medium yellow through out.

Term
In a TSI test, what does a yellow or reds slant with a black butt indicate?
Definition

red slant = glucose fermenation

yellow slant = glucose and lactose fermentation

Black = Hydrogen Sulfide

Term

Methyl Red - Voges Proskauer Tests , what does this IMViC test for?

 

What are the indications of a positive and negative for each?

 

What are the indicator reactants used?

Definition

Methyl Red tests for mixed acid fermentation and lowers overall pH. 

 

MR test: Postive = Red Yellow = Negative

 

Voges Proskauer Tests for organims that ferments glucose  produces acid and then quickly convert it to acetoin and butanediol.

 

VP test: Red = Positive Copper = Negative

 

 

Reactants used were: Methyl Red for MR test and Reagents A & B for VP

Term

Simmons Citrate Test is used to test for the presence of what?

 

What indicates a positive vs a negative?

Definition

It is used to test for the utilization of Citrate as an organisms sole source of Carbon. (Citrate Permease Enzyme)

 

Positive = Blue

Negative = Green

Term

Urea Broth Tests, tests for the presence of what?

 

What indicates a positive vs negative result?

Definition

It tests for the presence of Urease, which is an enzyme that breaks down Urea. 

 

Pink = Positive for presence of  Urease

Yellow = Negative for absence Urease

 

classic positive = Proteus vulgaris 

Term
What does SIM medium test for?
Definition

SIM medium tests for 3 things: Sulfur Reduction, indole production, and motility

 

 

Sulfur Reduction: results in Hydrogen Sulfide Production

Black = Positive for Hydrogen Sulfide

Yellow = Negative

 

Indole Production: 

Red Layer: positive for indole production

Clear Layer: negative for indole production

 

Motility:

If organisms are spaced and cloudy - positive for motility

Term

What does the Catalase Test differentiate?

Definition

Differentiates if an organism contains catalase or not, which breaks down Hydrogen Peroxide and results in a fizzing.

 

All Staphylococcus = Catalse Positive

All Streptococcus = Catalse Negative

Term

Blood Agars test for what?

 

What are the two types of Hemolysis?

Definition

They differentiate between some gram positives and their ability to break down RBC's via Hemolysins.

 

Alpha Hemolysis = incomplete lysis and results in a green appearance aroudn the colonys and not much clearing.

 

Beta Hemolysis = complete lysis of RBC = complete clearing around the growth as a result of complete lysis of RBCs.

Term
Coagulase Test is what type of test?
Definition

An Agglutination test similar to Blood Typing

 

It is Staph Aureus Positive ONLY!

Term
Bacitration is used to ID what organism? Why?
Definition
S. Pyogenes because it's sensitve to Bacitration and will not grow near it. 
Term

Bile Esculin Agar tests for what? 

 

What indicates a positive vs negative result?

Definition

Bile Esculin tests for Group D Enterics - Enterococcus 

 

Black = Positive

No color change = Negative

Term
What tests test with Gram Positive Organisms?
Definition
Blood Agar, Mannitol Salt, Mitis, Catalase Tests use Gram Positive
Supporting users have an ad free experience!