Stains, packet #4

Question 1

When staining Gram + with Crystal Violet what color does it retain?

Answer 1

Purple.

Question 2

At what stage in Gram - does the bacteria retain the pink dye?

Answer 2

the Safranin step.

Question 3

What are the four steps in Gram staining?

Answer 3

1. Crystal violet
2. Gram’s iodine
3. Acetone/ Alcohol
4. Safranin

Question 4

Which step is the decolorizing step in Gram staining?

Answer 4

Acetone/Alcohol

Question 5

If you forgot to add the counterstain to the mixed culture sample at the end of the staining procedure, gram-negative cells would appear __________ and gram-positive cells would appear __________.

Answer 5

Colorless; Purple.

Question 6

Are spore formers Gram negative or Gram positive?

Answer 6

Gram +

Clostridium & Bacillus

Question 7

All cocci are Gram positive except for?

Answer 7

Neisseria and Moraxella

Question 8

What is the Ziehl-Neelsen Stain used for?

Answer 8

Acid fast organisms

Question 9

What does Acid fast mean?

Answer 9

Acid fast is a physical property of certain bacteria (and, less commonly, protozoa), specifically their resistance to decolorization by acids during staining procedures.

Question 10

What reagents are used for Acid fast staining?

Answer 10

Carbol Fuchsin

Acid Alcohol

Methylene Blue

Question 11

For acid fast what color does the organism retain with all reagents?

Answer 11

Red

Question 12

For non acid fast what color does the organism retain with: Carbol Fuchsin?

Answer 12

Red

Question 13

For non acid fast what color does the organism retain with: Acid Alcohol?

Answer 13

Colorless

Question 14

When non acid fast retains a Blue color what reagent is being used?

Answer 14

Methylene Blue

Question 15

Do bacteria have a nucleus?

Answer 15

No

Question 16

What internal structures do Gram positive and Gram negative both have?

Answer 16

Nucleiod region

Plasmids

Mesosomes (though primarily Gram +)

Ribosomes

Granules

Question 17

What internal structure is exclusive to Gram + bacteria?

Answer 17

Endospores

Question 18

What in the function of endospores?

Answer 18

Resistance to heat, chemical and dehydration.

They are used for survival only!

Question 19

What is bacteriocin production and where is it produced?

Answer 19

Bacteriocin- is how bacteria are harmful to one another.

It is produced in the plasmids

Question 20

What chemical composition is in the nucleiod region?

Answer 20

DNA
RNA
Proteins

Question 21

Which bacterial structure is involved in protein synthesis?

Answer 21

Ribosomes

Question 22

What are granules made of and what is their function?

Answer 22

Made of glycogen, lipids, polyphosphate

They store food, and reduce osmotic pressure

Question 23

What structure is involved in Cell division and secretion

Answer 23

Mesosomes

Question 24

What are plasmids composed of?

Answer 24

DNA

Question 25

How do bacteria grow?

Answer 25

By binary fission

Question 26

During lag time is there an increase in number of bacterial cells?

Answer 26

NO

Question 27

During what phase is there rapid exponential growth?

Answer 27

Log phase

Question 28

What is the generation time?

Answer 28

The time it takes for one cell to divide into two.

Question 29

When is generation time determined?

Answer 29

During log phase

Question 30

When the nutrients are used up and toxic products like acids and alkalis begins to form, what phase is that?

Answer 30

The stationary phase

Question 31

What is the death phase?

Answer 31

The excretory phase (1. used up all nutrients, 2. living in waste)

Question 32

What is a selective medium?

Answer 32

A medium that selects for certain bacteria by inclusion of special nutrients and/or antibiotics.

Question 33

What is a differential medium?

Answer 33

A medium in which different bacteria can be distinguished by differences in colonial morphology or color.

Question 34

What mediums are used for Corynebacterium?

Answer 34

1. Lofflers coagulated serum medium (s) | 2. Tellurite agar (d)

Question 35

Enteric bacteria is cultured in what two mediums?

Answer 35

1. Eosin methylene blue (d) | 2. Mac Conkey's (d)

Question 36

Hektoen enteric agar (d) is used for what organisms?

Answer 36

Intestinal pathogens

Question 37

Legionella is cultured in what medium?

Answer 37

CYE (Charcoal-yeast extract agar) (s)

Question 38

Lowenstein-Jensen medium (s) is used to culture what organism?

Answer 38

Mycobacterium

Question 39

When is chocolate agar used for Neisseria?

Answer 39

from normally sterile sites

Question 40

Chocolate agar is used for what 2 organisms?

Answer 40

Neisseria (from normally sterile sites) Haemophilus

Question 41

Neisseria form sites with normal flora is cultured in?

Answer 41

Thayer Martin selective medium (s)

Question 42

What is the Thayer Martin medium supplemented with?

Answer 42

vancomysin, nystatin and colistin to inhibit normal flora

Question 43

Vibrio cholera is cultured in?

Answer 43

Thiosulfate Citrate Bile Salts Sucrose (TCBS) (s)

Question 44

Mycoplasma, Ureaplasma are cultured in?

Answer 44

Cholesterol, purines and pyrimidines

Question 45

Francisella, Brucella, Legionella and Pasteurella grow in ?

Answer 45

Cysteine

Question 46

Factors X ( protoporphyrin) and V (NAD) growth requirements are with?

Answer 46

Haemophilus ( influenza and aegypticus)