3-9

Question 1

what is a glycocalyx?

Answer 1

external structure around the cell wall produced by the bacterium

Question 2

what is a slime layer?

Answer 2

term used for glycocalyx that is loosely associated with the cell wall of bacterium

Question 3

what is a capsule?

Answer 3

term used for a glycocalyx tightly associated with cell wall of bacterium

Question 4

what is the glycocalyx (slime layer and capsule) composed of?

Answer 4

mucoid polysaccharides or polypeptides that repel most stains

Question 5

in capsule stain what does Congo red do?

Answer 5

stain the slide

Question 6

in capsule stain what does Maneval’s stain stain?

Answer 6

cell

Question 7

what stains the capsule?

Answer 7

capsule remains unstained

appears as while halo around cell

Question 8

what are the functions of the capsule?

Answer 8

1. avoidance of phagocytosis
2. reduces desiccation
3. protects against certain chemicals
4. aids in adherence
5. serves as nutrient source during starvation

Question 9

what is klebsiella pneumonia?

Answer 9

gram -

primary pneumonia is characterized by sudden onset and gelatinous reddish brown sputum (phlegm) (MO grows rapidly destroying lung tissue causing death)

secondary pneumonia is a nosocomial (hospital acquired) disease

Question 10

what is the most common infection caused by klebsiella

Answer 10

pneumonia

Question 11

steps of capsule staining?

Answer 11

1. add drop of Congo red
2. add MO and mix
3. take second slide and slide over slide with Congo Red
4. air dry (DO NOT HEAT FIX)
5. flood slide with Maneval’s stain
6. gently blot dry

Question 12

why do we not heat fix?

Answer 12

destroy capsule look like false negative

shrink cell look like false positive

Question 13

acidic stain

basic stain

Answer 13

acidic stain: stains slide

basic stain: stain cell

Question 14

what are the results of capsule staining?

Answer 14

klebsiella pneumonia + contains capsule

Staphylococcus aureus - no capsule