COLONIAL MORPHOLOGY Flashcards
IMPORTANCE OF COLONIAL MORPHOLOGY
• Provide a presumptive identification to the physician
• Enhances the quality of patient care through rapid reporting of results and by increasing the cost-effectiveness of laboratory testing.
• Play a significant role in quality control, especially of automated procedures and other commercially available identification procedures.
Lactose-fermenting, gram-negative rods producing_____ colonies on MacConkey (MAC) agar.
pink
Nonlactose-fermenting, gram-negative rods producing____ colonies on MAC agar.
colorless
Lactose-fermenting Escherichia/Citrobacter-like organisms growing on MacConkey (MAC) agar.
Notice the____ appearance of the colony and the____ precipitate of bile salts extending beyond the periphery of the colonies.
dry
pink
Klebsiella/Enterobacter-like lactose fermenters growing on MacConkey (MAC) agar.
Notice the ___, ___, _____appearance.
pink, umbonate, mucoid
GROSS COLONY CHARACTERISTICS
Hemolytic pattern
Form/ shape
Margin
Elevation
Density/ Opacity
Size
Consistency
Color
Pigment
ALPHA HEMOLYSIS
•______ hemolysis
Characterized by _____around the colonies
• Example:_____
GREENISH ZONES
Incomplete
Streptococcus pneumoniae
BETA HEMOLYSIS
•_____ lysis
Characterized by ______around the colonies
Example:
Complete
CLEAR ZONES
Streptococcus pyogenes
group A B-hemolytic streptococci (Streptococcus pyogenes), produce a __________of B-hemolysis,
• whereas others, such as group B B-hemolytic streptococci (Streptococcus agalactiae) and Listeria monocytogenes (a gram- positive rod) produce a_____, diffuse zone of B-hemolysis close to the colony.
wide, deep, clear zone
narrow
• Found in Clostridium perfringens
• Characterized by BETA HEMOLYTIC_____ zone of hemolysis due to production of theta toxin and in
ALPHA HEMOLYTIC_____ zone of hemolysis due to the presence of alpha toxin a.k.a lecithinase
DOUBLE ZONE OF HEMOLYSIS
inner
outer
Shape of bacillus
MEDUSA HEAD COLONIES;
LION FACE
SWARMING OF COLONIES
______- swarms on nonselective agar, such as blood or chocolate agar plate.
Proteus mirabilis
Diphtheroid
Rough
STARS OR COLONIES WITH FEET OR PEDICLES
Yeast
Pseudomonas aeruginosa
serrated
Actinomyces israelli
MOLAR TOOTH COLONIES
Form/ shape/ margin can be described as
smooth, filamentous, rough or rhizoid or irregular
Serrated
Pseudomonas aeruginosa
– MOLAR TOOTH COLONIES
Actinomyces israelli
SIZE
SIZE
Colonies can be described as
LARGE, MEDIUM, SMALL
SIZE
Streptococcus pyogenes have
COLONIES
Staphylococcus aureus have COLONIES
PINPOINT
PINHEAD
CONSISTENCY/TEXTURE
• Determined by…
touching the colony with a sterile loop
Consistency
• Canne described as:
• = Nocardia spp.
• = Staphylococcus aureus
• = some Neisseria, Klebsiella
• = Diphtheriods
Brittle, crumbly or wrinkled
Creamy
Sticky
Dry or Waxy
Color
Enterococcus are usually ______
• Diphtheroid are_____
Gray
buff colored
= blue green (pyocyanin – pyoverdin)
Pseudomonas aeruginosa
• = red (prodigiosin)
Serratia marcescens
= blue
Kluyvera
= violet (violacein)
• Chromobacterium violaceum
= brown - black
Provotella malaninogenica
DOUBLE ZONE OF HEMOLYSIS
• Found in…
• Characterized by BETA HEMOLYTIC____ zone of hemolysis (due to the production of theta toxin) and an ALPHA HEMOLYTIC___ zone of hemolysis (due to the presenc
Clostridium
inner
outer
ELEVATION
• Determined by tilting the plate and looking at the side of the colony
• Described as
flat, circular, raised, convex, umbilicate/crateriform, umbonate
Elevation
• Streptococcus pneumoniae are usually______
• Viridans are_____
• Beta hemolytic streptococci are generally____
umbilicate
umbonate
flat
DENSITY/OPTICAL PROPERTY
• Colonies are_____ if they allow all the light to pass through
• Colonies are_____ if they allow some of the light to pass through; Streptococcus agalactiae
Colonies are______ if they do not allow the light to pass through; Staphylococcus aureus
TRANSPARENT
TRANSLUCENT
OPAQUE
