U3 LAB: MICROSCOPIC MORPHOLOGY Flashcards
Uses one stain
Simple stain
Provides morphology and arrangement
Simple stain
Example of simple stain
Cocci in chains
Commonly used in Bacteriology
Differential stain
Provides Gram reaction, morphology, and arrangement
Differential stain
Primary stain
Crystal violet
Mordant
Gram’s iodine
Use of mordant
enhances primary stain to organism
Decolorizer
acetone alcohol
Use of decolorizer
removes primary stain
Secondary stain
Safranin
No mordant
secondary stain will be observed (pink)
- erroneous result
- false negative result
No alcohol
purple
- false positive result
Preparation of smear from clinical specimens
Direct smear
Cells observed in Direct Smear
- Bacterial cells
- RBCs, WBCs
Preparation of smear from culture
Indirect smear
Comma shaped bacilli
Vibrio
Not usually encountered, gram stain is not commonly done
Spiral
Gram (+) cocci in tetrads
Micrococcus tetragena
Gram (+) cocci in pairs (lancet shaped)
Streptococcus pneumoniae
Gram (-) cocci in pairs (may be found intracellularly inside PMN, coffee bean shaped)
- Neisseria sp. (N. meningitidis, N. gonorrhoeae)
Gram (+) cocci in sarcinae (cubical packet)
Sarcina lutea
Gram (+) cocci in chains
Streptococcus
Gram (+) cocci in clusters
Staphylococcus
Gram (+) bacilli in chains (large bacilli with square cut ends)
Bacillus
Bamboo fishing pole appearance
Bacillus
Clear structures in Bacilli
Endospores
Gram (-) bacilli in pairs
Pseudomonas or non-fermenters
Refers to elongated cocci
Coccobacilli
Gram (-) coccobacilli in pairs, singles
Enterics
Gram (+) bacilli that are large, arranged singly or inidividually with spores
- Clostridium tetani
- Clostridium botulinum
Spore of C. tetani is located?
terminally
Box car appearance
Clostridium perfringens
Gram (-) coccobacilli straight and rod shaped
Haemophilus ducreyi
- smallest pathogenic bacilli
- school of fish / railroad track pattern
Haemophilus ducreyi
Gram (-) bacilli with rounded ends
Bacteroides fragilis
Gram (+) large irregular bacilli
Corynebacterium
“club shaped” , Chinese Character, X or Y, palisade, snapping arrangement
Corynebacterium
Gram (+) branching bacilli with bifurcated or spatulated ends
Bifidobacterium
Gram (+) slender, branching, filamentous bacilli
Nocardia
T/F: Nocardia is also partially acid fast.
True
Gram (+) filamentous bacilli with a V-shaped pattern
Erysipelothrix rhusiopathiae
Erysipelothrix rhusiopathiae is the causative agent of?
Red disease
Gram (-) bacilli in long looped filamentous forms
Streptobacillus moniliformis
Streptobacillus moniliformis is also known as?
necklace bacillus
Gram (-) fusiform bacilli
Fusobacterium nucleatum
Gram (-) comma/curved shaped bacilli in singles
Vibrio
Gram (-) seagull wing shaped, S shaped bacilli
Campylobacter
Gram (-) curved bacilli with two or more curves
Spirillum
On gram stain, AFB is?
weakly gram positive
Acid Fast Bacilli Slender
Serpentine cord like pattern
Mycobacterium tuberculosis
AFB
Primary stain
Carbol fuchsin
AFB
Mordant
Heat / Tergitol
AFB
Decolorizer
Acid alcohol
AFB
Secondary stain
Methylene blue / Malachite green
Acid Fast Bacilli Slender
Palisades / globi packets / cigar bundle, arranged singly
Mycobacterium leprae
M. leprae is a causative agent of?
Leprosy
What microscope is used for Spirochetes?
Darkfield microscopy
What stains are used for Spirochetes?
- silver stains
- fluorescent stains
- tissue stains (Giemsa)
Tightly twisted, with one end or both bent to a hook
Leptospira interrogans
Leptospira interrogans resemble a?
Question mark
Motility of T. pallidum
Corkscrew motility
Flexibly twisted
Borrelia
This is the only spirochete that can be stained with Giemsa
Borrelia
Yeast cells are Gram ___
positive
Square shaped bacteria
Haloarcula spp.
Starshaped bacteria
Stella spp.
DSSM stands for?
Direct Sputum Smear Microscopy
What should be read before reporting sputum smear negative for ABF?
300 OIF
Structures seen in sputum smear
- WBC (pus cells)
- Squamous epithelial cells
- Mucus threads
Spiral shaped structures that can be seen in asthmatics
Curschmann’s Spirals
