Veterinary Interpretation Guide
Spectrum CS plate showing
Gram + and Gram - Spectrum
agars, Staphylococcus Select,
and TSA/Blood agars.
Enterobacter spp: Large
metallic blue colonies
surrounded by slight pink halo.
Enterococcus: Turquoise to
blue small colonies. Some
species may produce black
colonies on SS agar with no
media color change.
E. coli: Medium to large pink to
red colonies. Some rare species
may produce black colonies on
SS agar with no media color
change.
Klebsiella pneumoniae:
Medium metallic blue colonies.
+/- pink zone. Some species
may produce black colonies on
SS agar with no color change.
Proteus mirabilis: Clear to
slightly orange colonies
surrounded by brown pigment.
TSA/Blood: Gray mucoid
swarming growth.
Pseudomonas aeruginosa:
Transparent white to green
colonies with some diffusion
into media.
Grp. B Streptococcus: Light
blue pinpoint colonies. TSA/
Blood: Pinpoint colonies w/clear
zone of beta hemolysis. Some
species non-hemolytic.
Staphylococcus aureus:
Mauve to white colonies. Some
species light yellow. SS: Black
colonies surrounded by yellow
media.
Candida albicans (Yeast):
Can grow on all quadrants after
24 hours. Use Gram stain to
check for large budding cells.
Note: All organisms shown have been grown in pure culture. Mixed cultures should be interpreted with caution.
The Spectrum CS Culture System is for veterinary use only and is intended as an aid in the identification of
certain common pathogens. Presumptive results should be verified using traditional culture methods.
Copyright 2012 Vetlab Supply
Reorder from:
Vetlab Supply (800)3301522
Spectrum CS Culture System
Product # MCR-PLTSP500
Organism
(1) Spectrum Gram +
(2) Spectrum Gram -
(3) Staph. Select
(4) TSA w/5% Blood
Catalase¹
Oxidase²
No Growth
Some species may produce
small black colonies with
no color change to media.
Pinpoint semi-transparent
colonies with clear zone of
beta hemolysis. Some
3
species non-hemolytic V.
Neg
NA
Pinpoint to small smooth
colonies. Generally
non-hemolytic.
Neg
Neg
Group B Streptococcus
Light blue pinpoint colonies.
Enterococcus Spp.
Blue to turquoise
pinpoint colonies.
No Growth
Generally no growth. Some
species may produce
small black colonies.
No color change to media.
E. coli
No Growth
Medium to large pink
to red colonies.
Generally no growth. Some
are species may produce a
few black colonies with no
color change to media.
Medium size gray colonies
with characteristic odor. Most
species are non-hemolytic.V3
Pos
Neg
Staphylococcus aureus
Mauve to white colonies.
Some species may
3
appear pale yellow. V
No Growth
Black colonies surrounded
by yellow zone. See notes
regarding other species of
5
Staphylococcus.
Medium-sized white to gray
raised glistening colonies.
Clear zone of (beta) hemolysis.
Pos
NA
Proteus mirabilis
No Growth
Clear to slightly orange colonies
surrounded by brown pigment
diffusing into media.
Some species may produce
small black colonies with
no color change to media.
Gray mucoid growth swarming
over plate. Distinct colonies
are rarely seen. Brown
pigment diffusing into media.
Pos
Neg
Enterobacter Spp.
No Growth
Large metallic blue colonies
surrounded by pink halo.
No Growth
Large mucoid gray
colonies. Non-hemolytic.
Pos
Neg
No Growth
Medium size metallic blue
mucoid colonies; may or
may not be surrounded
3
by pink zone. V
May produce a few black
pinpoint colonies with no
color change to media.
Large mucoid gray
colonies. Non-hemolytic.
Pos
Neg
Pseudomonas aeruginosa
No Growth
Transparent slightly greenish
colonies w/some diffusion of
pyocyanin into media. Some
species reddish brown.
No Growth
Medium size gray or
bluish colonies with
some coalescing.
Pos
Pos
Candida albicans
Medium to large mauve
colonies. Some species may
3
produce white colonies. V
Small to medium
off-white colonies
Medium to large gray
mucoid colonies. No color
change to medium.
Moist, opaque white to gray
4
medium to large colonies.
NA
NA
Klebsiella pneumoniae
The Catalase test using 3% hydrogen peroxide may aid in differentiating Staphylococcus from Streptococcus species.
The Oxidase test can be helpful in differentiating Pseudomonas aeruginosa from other Gram negative bacteria and some Staphylococcus species. Oxyswab®
(Prod. #MCR-GL60500) affords a simple method for performing this test.
3
Indicates the potential for variability in color and growth characteristics of certain organisms.
4
Candida albicans and other yeasts will generally grow in all quadrants. Use Gram stain to differentiate from bacteria. Yeasts will appear as large, Gram positive
budding cells.
5
S. saprophyticus and S. epidermidis are considered non-pathogens that will form gray black colonies without yellow zones. S. intermedius exhibits a reaction similar
to S. aureus. Additional methods are required for differentiation.
1
2