CHAPMAN Agar

EMD Cat. No. 1.05469.0500
500 g


For the isolation and differentiation of staphylococci in foodstuffs and other materials according to CHAPMAN (1946, 1948, 1952).



Mode of Action Preparation
Experimental Procedure and Evaluation Quality Control
Typical Composition (g/liter) Literature
Picture/Image


Mode of Action
 Only those microorganisms which display a high salt tolerance can grow on this culture medium; these include staphylococcal colonies, which can be differentiated on the basis of mannitol degradation, gelatinolysis and pigment production.
 SMUCKLER and APPLEMAN (1964) recommend the addition of sodium azide (65 mg/liter) to improve the inhibition of Bacillus species.

Typical Composition (g/liter)
 Peptone from casein 10.0; yeast extract 2.5; di-potassium hydrogen phosphate 5.0; gelatin 30.0; lactose 2.0; D(-)mannitol 10,0; sodium chloride 75.0; agar-agar 12.0.

Preparation
 Suspend 146.5 g in 1 liter of purified water. Autoclave (15 min at 121°C). Pour plates.
pH: 7.0 ± 0.2 at 25°C.
 The plates are clear and yellowish-brown.

Experimental Procedure and Evaluation
 Inoculate the plates by spreading the sample on the surface of the medium.
 Incubation: 48 hours at 35°C aerobically.
Pigment-forming colonies are golden yellow, non-pigmented colonies are white.

Formation of acid from mannitol is indicated by a color change to yellow, when drops of a 0.04% bromothymol-blue solution are applied to colony sites; the individual colonies should first be removed with a platinum loop.
According to STONE (1935), gelatinolysis is an indicator of toxicity and it is shown by the appearance of clear zones around the colonies about 10 minutes after applying drops of a saturated ammonium sulfate solution or a 20% sulfosalicylic acid solution.
Further tests should be performed to confirm the results.

Quality control

Test strains
 Growth
Staphylococcus aureus ATCC 25923
 		good/ very good
Staphylococcus aureus ATCC 6538-P
 		good / very good
Staphylococcus simulans ATCC 11631
 		good / very good
Staphylococcus epidermidis ATCC 12228
 		fair / very good
Escherichia coli ATCC 25922
 		none
Proteus vulgaris ATCC 13315
 		none
Pseudomonas aeruginosa ATCC 27853
 		none
Streptococcus pyogenes ATCC 12344
 		none


Additives


EMD Cat. No. Product Pack Size
SX1220-3 5-sulfosalicylic acid dihydrate 125 g
B10033-34 Ammonium sulfate 500 g
BX1555-5 Bromothymol blue indicator 25 g
0066884R Sodium Azide, Extra Pure 100 g


Literature

CHAPMAN, G.H.: A single culture medium for selective isolation of plasma coagulating staphylococci and for improved testing of chromogenesis, plasma coagulation, mannitol fermentation and the Stone reaction. J. Bact., 51; 409-410 (1946).
 CHAPMAN, G.H.: An improved Stone medium for the isolation and testing for food-poisoning staphylococci. Food Res., 13; 100-105 (1948).
 CHAPMAN, G.H.: A simple method for making multiple tests of a microorganism. J. Bact. 63; 147 (1952).
 SMUCKLER, S.A., a. APPLEMAN, M.D.: Improved staphylococcus medium no. 110. Appl. Microbiol. 12; 355-359 (1964).
 STONE, R.V.: A cultural method for classifying staphylococci as of the "food poisoning" type. Proc. Soc. Exptl. Biol. Med., 33; 185-187 (1935).


Staphylococcus aureus



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