U2.1.1 L : Experiment 6-7 Flashcards
Differential Staining
Principle : used to distinguish if the isolate is Gr (+) or Gr (-)
Gram Staining
Gram Staining
Gram (+) bacteria : color
stained purple
Gram Staining
Gram (-) bacteria : color
stained red
T/F Gram Staining is based on the reaction of bacterial cell wall on staining solutions
T
Two Types of Smear
prepared from colonies growing from plated media
Indirect Smear
Two Types of Smear
prepared from clinical specimen
Direct Smear
Staining Procedure Gram Stain
Stain :
Mordant :
Decolorizer :
Counterstain :
Stain : Crystal Violet for 1 minute
Mordant : Gram’s Iodine for 1 minute
Decolorizer : Acetone-alcohol or 95% Ethanol for 10 seconds
10 seconds
Counterstain : Safranin O for 30 seconds
T/F In Gram staining smear should have pink/red or clear background and cells are overlapping
F, cells should not be overlapping
Gram staining
Examine smear _____/____ scanning
Horizontal / Vertical Scanning
Microscopic Examination : Direct Staining
Microscopic Structures Present
Epithelial Cells, PMNs, RBCs, Host cellular material
Gram Staining
Microscopic Examination : Enumeration of Cells under LPO
1+
1+ = </LPF
Gram Staining
Microscopic Examination : Enumeration of Cells under LPO
2+
2+ = 1-9/LPF
Gram Staining
Microscopic Examination : Enumeration of Cells under LPO
3+
3+ = 10-25/LPF
Gram Staining
Microscopic Examination : Enumeration of Cells under LPO
4+
4+ = >25/LPF
Gram Staining
Microscopic Examination : Enumeration of Bacteria under OIO
1+
1+ (rare or occasional) = <1/OIF
Gram Staining
Microscopic Examination : Enumeration of Bacteria under OIO
2+
2+ (few) = 1-5/OIF
Gram Staining
Microscopic Examination : Enumeration of Bacteria under OIO
3+
3+ (moderate) = 6-30/OIF
Gram Staining
Microscopic Examination : Enumeration of Bacteria under OIO
4+
4+ (heavy) = >30/OIF
Differential Staining
Principle : For the detection of Tubercle bacilli in sputum specimen
AFS
AFS
What does it detect in sputum specimens
Tubercle bacilli
T/F In AFS, Tubercle bacili resist decolorization w/ acid-alcohol and appear red on a blue / green background after decolorization
T
AFS
Causative agent of Mycobacterium Tuberculosis
Tubercle bacilli
AFS
Primary diagnostic and monitoring tool for TB
Direct Sputum Smear Microscopy
AFS
Specimen Considerations
Time
Collected preferably early morning
AFS
Sputum should be ____
Sputum should be thick, cloudy, and sticky
AFS Procedure
Smear should be spread properly showing ____ patterns
concentric / coil-like patterns
AFS
Stain
0.3% Ziehl’s Carbol Fuchsin
AFS
Decolorizer
Acid alcohol
AFS
Counterstain
0.3% Methylene blue / Malachite Green
AFS Microscopic Examination
Manner of scanning
From left to right go downward a bit and then right to left
AFS
Microscopic Structures Present
Squamous Cells, Leukocytes, Mucus Threads, Bacterial cells aside from AFB
AFS
Color of Bacterial Cells aside from AFB
Blue and green
AFS
Color & Morphology of AFB
red or pink bacilli; thin,
filamentous or beaded
Enumeration of AFB under OIO
+n
+n : 1 - 9 AFB seen in 100 OIF
Enumeration of AFB under OIO
1+
1+ : 10-99 AFB seen in 100 OIF
Enumeration of AFB under OIO
2+
2+ : 1-10 AFB/OIF in at least 50
fields
Enumeration of AFB under OIO
3+
3+ : >10 AFB/OIF in at least 20
fields
Special Staining
T/F Pathogenic organisms have a protected covering made up of polysaccharide polymer and polypeptide
T
Special Staining
Stain used for Capsules
India ink / Nigrosin
Special Staining
Appears halo-like against stained
amorphous background
Capsule
Special Staining
A virulence factor which inhibits phagocytosis
Capsule
Special Staining : Capsule
Specimen
Klebsiella pneumoniae on a nutrient agar slant or plate
Special Staining
multilayered ovoid or spherical structures present inside Gr (+) bacteria
Endospores
Special Staining
Seen among Bacillus and Clostridium
Endospore
Special Staining
Organisms with endospores
Bacillus & Clostridium
Special Staining
Can be found centrally, subterminal, or terminal
Endospore
Special Staining : Spore
T/F Endospores are highly resistant to heat, desiccation, and chemical disinfectant
T
Special Staining : Spore
Main component of spore
Calcium dipicolinate or dipocolonic acid calcium complex
Special Staining : Spore
appear as _____ structure
clear structure
Special Staining : Spore
Technique used
Schaeffer-Fulton Method
Special Staining : Spore
Specimen
Pure colonies of Bacillus subtilis in a nutrient slant or plate
Special Staining : Spore
Stain used
6.5% Malachite green
Special Staining : Spore
Counterstain + time
Safranin O for 30 seconds
Special Staining : Spore
Endospores stain ____
green
Special Staining : Spore
Vegetative cells stain ____
red/pink
Special Staining
stained using Leifson staining technique
Flagella
Special Staining : Flagellar
most common stain used
Leifson staining method
Special Staining : Flagellar
Leifson staining technique
Primary Stain
Basic fuchsin
Special Staining : Flagellar
Leifson staining technique
Mordant
Tannic Acid
Special Staining : Flagellar
Leifson staining technique
Counterstain
Methylene Blue
Special Staining : Flagellar
Properly prepared bacterial suspension = [appearance]
slightly cloudy
Special Staining : Flagellar
when do you wash the smear with distilled water [2 indicators]
- golden precipitate is formed on the dye surface
- precipitates appear on the smear
Special Staining : Flagellar
color of bacterial cells and flagella
red
Special Staining : Flagellar
devoid of flagella
Atrichous
Special Staining : Flagellar
flagella on one pole/end
Monotrichous
Special Staining : Flagellar
a tuft/group of flagella on one pole/end
Lophotrichous
Special Staining : Flagellar
flagella on both poles/ends
Amphitrichous
Special Staining : Flagellar
surrounded with flagella
Peritrichous
Test for Motility
non-staining method for demonstration of presence of flagella
Hanging Drop Method
Test for Motility
long, proteinaceous filaments for
locomotion
Flagella
Test for Motility
Considered as a virulence factor
Flagella
Test for Motility
Presence or absence is interpreted as
Presence = motile
absence = non-motile
Test for Motility
used for serotyping
Flagellar antigens
Test for Motility : HDM
Appearance of bacterial cells
appear translucent with slight greenish color
Test for Motility : Hanging Drop Method
Specimen
Broth cultures of known motile or non-motile bacteria
Test for Motility : HDM
True Motility : [movement]
bacterial cells exhibit directional
purposeful movement
Test for Motility : HDM
Non-motile bacteria movement
Brownian movement
Test for Motility : HDM
random jiggling or shaking due to bombardment of water molecules
Brownian movement
Test for Motility : Use of SIM
Specimen
Broth cultures of known motile or non-motile bacteria
Test for Motility : Use of SIM
Medium
Sulfide Indole Medium
Test for Motility : Use of SIM
Incubation of medium
____ hrs at ____ C
18 - 24 hrs at 35 - 37°C
Test for Motility : Use of SIM
Growth Pattern : bacterial growth is away from the site of inoculation
Motile
Test for Motility : Use of SIM
Growth Pattern : bacterial growth is limited to the site of inoculum
Non-motile
Test for Motility : Use of SIM
Appearance of Motile
Appears diffuse or hazy
Test for Motility : Use of SIM
Appearance of Non-motile
Surrounding medium is clear
Test for Motility : Use of SIM
Inoculate culture by making a [action] down the center of the tube about [depth] of the medium
stab using inoculating needle;
3/4 the depth
Gram Staining Procedure
Reagents + Time
- Crystal Violet 1 minute
- Gram’s Iodine 1 minute
- 95% Ethanol or Acetone Alcohol 10 seconds
- Safranin O or Carbol Fuchsin 30 seconds
AFS : Ziehl Neelsen Staining Procedure
Reagents + Time
- Carbol Fuchsin 10 mins
- Steam
- Acid Alcohol 3 mins
- MB / MG less than 1 minute
AFS
Reason why we use heat after flooding Carbol Fuchsin
to enhance penetration of dye to the cells
AFS
Reason for using filter paper during staining
to avoid drying out
Test for Motility HDM
Petroleum jelly is used to
seal cover slip & drop of bacteria; to keep it from drying out
Spore Staining Procedure
Reagents + Time
- Malachite Green 10 mins
- Safranin O 30 seconds
Flagellar Staining Procedure
Reagents + Time
- Leifson dye 7-15 mins
Test for Motility HDM
Slide used
concavity slide
Test for Motility HDM
Bacterial cells would appear as
translucent with slight
greenish color