CELLOBIOSE POLYMYXIN B COLISTIN AGAR, MODIFIED ( m CPC Agar )
CAT Nº: 2015
For the cultivation of vibrio species in food
FORMULA IN g/l
Sodium Chloride
20.0
Cellobiose
10.0
Peptone
10.0
Colistin
400.000 IU
Beef Extract
5.00
Polymixin B
100.000 IU
Bromothymol Blue
0.04
Bacteriological Agar
15.00
Cresol Red
0.04
Final pH 7.6 ± 0.2 at 25ºC
PREPARATION
Suspend 60.2 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent
agitation. Boil for one minute until complete dissolution. Dispense into appropriate containers. DO NOT AUTOCLAVE. The
prepared medium should be stored at 8-15°C. The color is green purple.
The dehydrated medium should be homogeneous, free-flowing and light beige in color. If there are any physical
changes, discard the medium.
USES
CELLOBIOSE POLYMYXIN B COLISTIN AGAR, MODIFIED (m CPC Agar) is used for the cultivation of Vibrio species that
are pathogenic to humans causing cholera, choleral diarrhea or food poisoning from contaminated foods, water and from
stool specimens.
It has the same formulation as CPC AGAR (Cat. Nº 2030) with less concentration of cellobiose and less concentration of
Colistin that make the medium less selective.
Peptone and Beef Extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride
supplies essential electrolytes for osmotic balance. Cellobiose is fermented by some Vibrios producing acid and is
indicated by the pH indicator bromothymol blue, which turns to yellow. Cresol red is the pH indicator of alkaline range,
which turns red at alkaline pH. Alkaline pH of the medium enhances the recovery of Vibrios. Colistin and polymyxin B are
both fatty acyl decapeptide antibiotics with bactericidal activity against most gram-negative bacteria.
It is claimed that raising the medium’s pH leads the medium’s alkalinity to inhibit most of the unwanted flora
background, leaving the viability of the Vibrio species intact.
Inoculate from an incubated Alkaline Peptone Water (Cat. Nº 1407) and incubate at 35 ± 2°C for 18- 24 hours.
Typical colonies of V. cholerae on m CPC agar are small, smooth, opaque, and green to purple in color, with a purple
background on extended incubation.
1
LABORATORIOS CONDA, S.A.
www.condalab.com
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a
temperature of 35 ± 2°C and observed after 18 – 24 hours.
Microorganisms
Vibrio cholerae ATCC 14034
Growth
Colony Color
Good
Green-purple
BIBLIOGRAPHY
Bacteriological Analytical Manual Chapter 9 Vibrio
STORAGE
25ºC
Once opened keep powdered medium closed to avoid hydration.
2ºC
2
LABORATORIOS CONDA, S.A.
www.condalab.com