Description: For
food, rapid detection of Staphylococcus aureus in water, milk, ice cream and
meat products, the results will turn out within 24 hours. The colonies of Staphylococcus
aureus are blue-green, Listeria is purple, and most of Gram-negative bacteria are
inhibited.
Ingredients (g / L)
Nutrients
|
25.0
|
Chromogenic
reagent
|
40.3
|
Agar
|
15.0
|
Bacteriosestatic
agent
|
6.0
|
Final pH 7.2-7.4
at 25 ℃
|
*Adjusted and/or supplemented as required
to meet performance criteria.
Directions:
Suspend 17.26g/200mL; boil in 2.-3 minute, when
cooling to 50℃ into sterile petri dishes.
Procedures:
Coating
method:
1. Prepared sample solution according to
national standards, SN standard, FDA standards or other methods.
2. Transfer 1ml sample solution with appropriate
dilution onto the center of Staphylococcus aureus chromogenic medium plate of dry
surface, each dilution of medium is made into two plates;
3. Coat sample solution to the agar surface
with an L-shaped glass rod, avoid to coat on plate edge, put the plate upright
until the liquid is absorbed by the sample medium;
4. Put inverted into incubator at 36 ± 1 ℃ for 18-24h, typical of
Staphylococcus aureus protuberant blue-green colonies;
5. Counting all protuberant blue-green
colonies on plate.
Streak
method:
1. Prepared sample solution according to
national standards, SN standard, FDA standards or other methods.
2. Take 10ul-20ul sample solution, streaked
on solidified Staphylococcus aureus chromogenic medium plates
3. Place inverted in incubator culture at 36
± 1 ℃ for 18-24h, typical of
Staphylococcus aureus protuberant blue-green colonies
Note: Staphylococcus aureus is Gram-positive
cocci by microscopic examination and rabbit plasma coagulase test is positive
Quality Control:
1. Appearance:
The dehydrate powder medium is homogeneous,
having good flow ability; pale yellow or pale pink, prepared medium is
colorless solid.
2. Microbial sensitivity test:
Incubated at 36 ± 1 ℃ 18-24h:
QC Strains
|
Strains No.
|
Growth
|
Colonies color
|
Listeria monocytogenes
|
ATCC27853
|
+
|
purple
|
Staphylococcus aureus
|
ATCC25923
|
+++
|
Blue-green
|
Staphylococcus epidermidis
|
CMCC29069
|
-/+
|
colorless
|
E. coli
|
ATCC25922
|
-/+
|
colorless
|
salmonella
|
ATCC14028
|
-/+
|
colorless
|
Bacillus cereus
|
|
-/+
|
colorless
|
Typical features:
Typical of Staphylococcus aureus protuberant
blue-green colonies; observe the results within 24 hours.
Storage:
The prepared plates can be kept in 2-5 days,
avoid direct exposure to light. The powder medium should be placed in a dark,
dry place, storage temperature 2-8 ℃, avoid direct exposure to light.
Failure:
Dry powder media which are over the shelf
life, caking and color variation cannot be used.
Note:
This medium is only for laboratory use.
Reference:
1. Beckers H. J., van Leusden F. M., Hogeboom
W. M. and Delfgon-van Asch E. H. M. (1980) (English summary) De
Ware(n)-Chemicals 10. 125-130.Enterobacteriaceae. Ann. Inst. Pasteur (Paris),
102; 267-277 (1962).
2. Beckers H. J., van Leusden F. M.,
Bindshedler O. and Guerraz D. (1984) Can. J. Microbiol. 30. 470-474.
3. Baird-Parker A. C. (1962) J. Appl.
Bacteriol. 25. 12-19