U3 LEC: COLONIAL MORPHOLOGY Flashcards
Importance of Colonial Morphology as a Diagnostic Tool
- provide presumptive diagnosis
- enchanced quality of patient care through rapid results and cost-effectiveness
- plays a significant role in quality control
Observed in media immediately surrounding or underneath the colony
Hemolysis
Hemolysis
Most important in presumptive identification of?
Streptococcus
Hemolysis
Uses what light source?
Transillumination (light source behind the plate)
Hemolysis
Two major types
a-hemolysis
B-hemolysis
Hemolysis
Partial clearing of blood, green discoloration
a-hemolysis
Hemolysis
Examples of a-hemolytic bacteria
Streptococcus pneumoniae, viridans strep
Hemolysis
Complete clearing of blood cells
B hemolysis
Hemolysis
Examples of B hemolysis
- S. pyogenes
- S. agalactiae
- Listeria monocytogenes
Hemolysis
Non hemolytic colonies are referred to as?
y hemolytic
Colony size
- Large
- Medium
- Small
- Pinpoint
This helps suggest what you might find on Gram stain
Colony Size
Colony Size
Gram-positive is ____ than gram-negative
less
Colony Size
Staphylococcus is _____ than Streptococcus
greater
Edge of colonies
- Smooth
- Filamentous
- Rough
- Rhizoid
This bacteria has filamentous edge of colonies.
Bacillus anthracis
These bacterial colonies have rough edges.
Diphtheroid
Form or Margin
This is referred to as a hazy blanket of growth on surface.
Swarming
Form or Margin
Examples of bacteria with Swarming colonies
Proteus spp.
Description of a colony in which light can pass through
Transluscent colony
T/F: There is no such thing as colorless or transparent colony.
True
Elevation
- Raised
- Convex
- Flat
- Umbilicate
- Umbonate
Elevation
Raised flat top
Raised
Elevation
Dome shaped
Convex
Elevation
Not raised
Flat
Elevation
Convex with depressed center (pitting)
Umbilicate
Elevation
Examples of Umbilicate
S. pneumoniae (if no capsule)
Elevation
Convex with protruding nipple
Umbonate
Elevation
Examples of Umbonate
Diphtheroids
Density
- Transparent
- Transluscent
- Opaque
Semiopaque (bull’s eye colony)
Group B strep (mostly Staph and Gr (-) rods)
Color
Coagulase negative staph
White
Color
Enterococcus and most gram-negative rods
gray
Color
Micrococcus and Neisseria
yellow or off-white
Color
Diphtheroids
buff
This is determined by touching a colony with a loop.
Consistency
Consistency
- Brittle (splinters)
- Creamy
- Dry
- Waxy
- Sticky
Consistency
Entire colony comes off the plate
Sticky
Consistency
Creamy
Staphyloccocus aureus
Consistency
Sticky
Neisseria
Consistency
Brittle
Nocardia
Consistency
Dry
Streptococci
Consistency
Dry and waxy
Diphtheroid
Pigment
Green or green metallic sheen
Pseudomonas aeruginosa
Pigment
Brick red
Serratia marcescens
Pigment
Blue
Kluyvera
Pigment
Purple
Chromobacterium violaceum
Pigment
Brown-black anaerobe
Prevotella melaninogenica
Odor
Old sock
S. aureus
Odor
Fruity or grape-like
P. aeruginosa
Odor
Putrid
Proteus mirabilis
Odor
Musty basement
Haemophilus spp.
Odor
Freshly plowed field
Nocardia spp.
Organisms in Liquid Media
Streamers
- Vinelike growth
- Scumlike growth
Organisms in Liquid Media
Vinelike growth, puff ball-like
Streptococci
Organisms in Liquid Media
Scumlike growth
Yeast
Organisms in Liquid Media
Refers to overall cloudiness of liquid
Turbidity
Organisms in Liquid Media
Gas bubbles present
Enterics
Oxidative processes require?
oxygen
What medium is used in Carbohydrate oxidation and fermentation?
Oxidative-fermentative medium
This determines the ability of bacteria to produce enzymes
Amino acid degradation
What medium is used for amino acid degradation?
Lysine Iron Agar (LIA)
Enzymes in amino acid degradation can:
- Deaminate
- Dihydrolyze
- Decarboxylate
Level 1: Critical/invasive
- Amniotic fluid
- blood
- brain
- CSF
- heart valve
- pericardial fluid
Level 2: Unpreserved
- Bloody fluids
- Bone
- wound drainage
- feces
- sputum
- tissue
Level 3: Quantitation Required
- Catheter tip
- Urine
- Tissue for quantification
Level 4: Preserved
- Feces in preservative
- Urine in preservative
- Swabs in holding medium
Traditional Biochemical Testing Panel
- Citrate
- TSI
- LIO
- MIO/SIM
- Urease
- Glucose
- Lactose
- Maltose