Exercise 7_ Bacterial Capsule

Question 1

mainly composed of polysaccharides but may contain polyalcohol and polyamines

Answer 1

capsules

Question 2

capsules are composed of (3)

Answer 2

polysaccharides polyalcohol polyamines

Question 3

location of capsule in gram positive bacteria

Answer 3

external to the cell wall

Question 4

bacteria with capsule that is external to the cell wall

Answer 4

gram positive bacteri

Question 5

location of capsule in gram negative bacteria

Answer 5

external to the outer membrane

Question 6

bacteria with capsule that is external to the outer membrane

Answer 6

gram negative bacteria

Question 7

this refers to when the material is tightly bound and remains attached to the cells and there is a defined shape

Answer 7

capsule

Question 8

this refers to when the material is loosely bound and there is no distinct boundary

Answer 8

slime layer or glycocalyx

Question 9

slime layer is also known as

Answer 9

glycocalyx

Question 10

glycocalyx is also known a

Answer 10

slime layer

Question 11

functions of capsules

Answer 11

• allow the cells adherence to surfaces - protects cells from desiccation, chemical and physical inhibitory factors - contribute to biofilm formation - can boost bacteria’s virulence (protecting them from the host’s immune system) - confer to the cells antigenic determinants leading to variation in pathogenicity - resist phagocytosis - exclusion of bacterial viruses and hydrophobic toxic materials

Question 12

what were developed based on bacterial antigenicity

Answer 12

some vaccines

Question 13

some vaccines were developed based on the ____ ___ of a bacteria

Answer 13

capsule antigenicity

Question 14

aids that can help visualize the capsule/slime layers

Answer 14

• electron microscopy - phase contrast microscopy - various staining techniques - special media

Question 15

3 staining methods employed in this exercise

Answer 15

• Duguid’s method/negative staining - anthony’s method - maneval’s staining method

Question 16

_____ ____ with the use of ink will provide a colored background as the large particles of ink will neither penetrate the tight layers of the capsule nor stain the bacterium

Answer 16

negative staining

Question 17

negative staining will only stain the _____ of the cells as the large particles of the ink will neither penetrate the tight layers of the capsule nor stain the bacterium

Answer 17

background

Question 18

charge of basic dye

Answer 18

positive

Question 19

basic dye interacts with the ____ ions of the bacterial cell wal

Answer 19

negative

Question 20

it interacts with the negative ions of bacterial cell

Answer 20

basic dye

Question 21

charge of acidic stain

Answer 21

negative

Question 22

acidic stain is used to color which part of the specimen>?.

Answer 22

background

Question 23

basic stain is used to color which part of the specimen>?.

Answer 23

cells

Question 24

indication of capsulated cells after staining

Answer 24

clear halo b/w the colored background and the stained cell

Question 25

what does the clear halo b/w the colored background and the stained cell indicates

Answer 25

presence of capsule

Question 26

examples of mordants

Answer 26

metal ions alcohol acetic acid

Question 27

function of mordant

Answer 27

precipitate the capsular material to make it visible

Question 28

this aid in the precipitation of capsular material for better visualization

Answer 28

mordant

Question 29

control organisms used for this exercise

Answer 29

B polymyxa

Question 30

culture media utilized for this exercise

Answer 30

Nutrient agar w/ 2% glucose Nutrient agar w/ 2% sucrose

Question 31

percent concentration of the glucose and sucrose added to NA

Answer 31

0.02

Question 32

mounting medium of negative staining/duguid's method

Answer 32

india ink/nigrosin

Question 33

this method utilizes india ink/nigrosin as mounting medium

Answer 33

negative staining/duguid's method

Question 34

can mounts for capsular observation be heat fixed?

Answer 34

NO

Question 35

Mounting medium of anthony's method

Answer 35

6% glucose soln

Question 36

this method uses 6% glucose soln as a mounting medium

Answer 36

anthony's method

Question 37

percent concentration of the glucose solution for anthony's method

Answer 37

0.06

Question 38

primary stain of anthony's method

Answer 38

crystal violet

Question 39

time requirement in using crystal violet as a primary staining agent in anthony's method

Answer 39

2 min

Question 40

instead of water, this is used to wash crystal violet in anthony's method

Answer 40

copper sulfate

Question 41

in duguids method/negative staining the capsules will appear as ____ ____

Answer 41

clear zones

Question 42

this method results to capsules being seen as clear zones, with refractile cells and brownish-black background

Answer 42

negative staining/duguids method

Question 43

in duguid's method/negative staining the cells will appear as

Answer 43

refractile cells

Question 44

in duguid's method/negative staining the background will appear as

Answer 44

brownish black

Question 45

this method results to capsules being seen as light blue to colorless, with blue/dark purple cells

Answer 45

anthony's method

Question 46

in anthony's method the capsules will appear as

Answer 46

light blue to colorless

Question 47

in anthony's method the cell will appear as

Answer 47

blue/dark purple

Question 48

mounting medium of maneval's staining method

Answer 48

congo red

Question 49

which method uses congo red as a mounting medium

Answer 49

maneval's staining method

Question 50

after emulsifying the samples in congo red, the next staining agent is

Answer 50

maneval's stain

Question 51

time requirement in using maneval's stain in anthony's method maneval's staining method

Answer 51

5-10 mins

Question 52

bakit naglalagay ng tissue sa ibabaw ng smear preps before maglagay ng staining agents

Answer 52

para walang debris na matransfer dun sa sample

Question 53

amount of india ink/nigrosin that is mounted in the glass slide

Answer 53

loopful

Question 54

amount of 6% glucose solution that is mounted in the glass slide

Answer 54

loopfu

Question 55

amount of congo red that is mounted in the glass slide

Answer 55

a drop

Question 56

what do we use to rinse the maneval's stain

Answer 56

water

Question 57

in anthony's method, this component helps prevent the capsule shrinkage

Answer 57

glucose solution

Question 58

pH indicator component of maneval's staining metho

Answer 58

congo red

Question 59

at or below pH 3.0 congo red turns to

Answer 59

blue

Question 60

at what pH congo red turns to blue

Answer 60

pH 3.0

Question 61

above pH 5.2 congo red turns to

Answer 61

red

Question 62

at what pH congo red turns to red

Answer 62

above pH 5.2

Question 63

the component of maneval's staining method that increases the penetration of the stain

Answer 63

phenol

Question 64

the component of maneval's staining method that acts as a chemical fixativ

Answer 64

FeCl3

Question 65

the component of maneval's staining method that penetrates the exopolysaccharide layer of the cell

Answer 65

acid fuchsin

Question 66

the component of maneval's staining method that changes the background from red to blue

Answer 66

acetic acid

Question 67

why are smears for capsule staining not fixed by heat?

Answer 67

- highly hydrated molecule, can be diminished, desiccated, distorted, or destroyed by heating - can alter the overall morphology of the bacterial cells - produce a clear area around the cell that can mistakenly be identifies as a capsul

Question 68

condition/s where the capsule is formed

Answer 68

- response to nutrient limitation or stress conditions