LO5

Question 1

which micrsocope do we use to view gram stain

Answer 1

light (or bright field) microscope

Question 2

direct gram vs culture gram

Answer 2

direct: using a sm amount of original clinical speciment

culture gram: using a bcterial colony following plating and incubation or from a tube

Question 3

4 benefits to performing a direct gram

Answer 3

1. preliminary evaluation of pathogen presence
2. appropriate media was used based on the gram stain pathogen morphology
3. knowing which batceria was in the gram allows for interpretation of colonies based on the growth
4. give the physician a preliminary idea about the possible etiologic agents of infection

the only ones who dont get a direct gram: throat swabs and feces

Question 4

Q-score

Answer 4

-performed on sputum
-By viewing the Gram stain, a technologist will compare the number of squamous epithelial cells coming from the skin surface of the mouth to the number of pus cells

-if mouth flora is too much you reject

Question 5

direct smears : swabs

Answer 5

-roll swab on each side of glass
-then innoculate plates
-liquid media last

Question 6

direct smears: fluids

Answer 6

such as CSF, use a Pasteur pipette

do not spread

Question 7

direct smears: tissues

Answer 7

-touch prep
-touch the cut tissue on the slide
-the grind that tissue for the culture media

Question 8

direct smears: Mucoid, Thick or Purulent

Answer 8

sputum - sterile

used a sterile loop or, possibly, a swab

-spread so that the smear is thin

Question 9

culture gram

Answer 9

-after growth on a culture
-if the organism is coming from a plate then you would pick one up and touch plate and then you would emulsify with saline

Question 10

fixation 4 reasons

Answer 10

-kill vegetative organism
-preserve bacterial cells
-improve penetration of stain
-imporove adhesion of bactetia

Question 11

3 ways to get fixation

Answer 11

1. micro incinirator fro 10 sec
2. 60 C slide warmer 10 min
3. 95% methanol, 1 min, preserving bacterial morphology and RBC, WBC and skin cells

Question 12

gram +

Answer 12

-teichoic acid
-lipoteichoic acid
-more peptidoglycan
-pore size is smaller
-when the dye combines with the iodine it will have a weight that cannot pass though
-iodine traps
-decolorizing resistant

Question 13

gram -

Answer 13

-high lipid content, the outside has lipo…
-this allows for alcohol to penetrate

Question 14

decolorizing

Answer 14

-acetone is quick
-alcohol is slow, thinner smears
-usually used as a combination of equal parts
-time depends on thickness

Question 15

gram stain steps

Answer 15

primary stains: crystal violet
trapping agent : iodine
decolorizer: acetone - alcohol
counterstain: safranin

Question 16

gram stain QC

Answer 16

should have a + and - , usually neg bacilli and cocci pos

Question 17

troubleshoot

gram + is red
gram + is red/purple

gram neg - red/ purple
gram neg- purple

no control organism present
brown artifact

Answer 17

over decolorized , old
over decolorized , old

under decolorized
under decolorized

not fixed
over fixed/ scorched