BacterPlate™ Columbia Agar (CBA)

Ready-to-use chromogenic medium on 90mm plates for culturing and isolating of fastidious microorganisms
Code: 05008
Packaging: 10 plates/ box or as per customer request.
Storage Conditions: 2–8°C.
Transportation: Ambient temperature.
Shelf Life: 03 months from the date of manufacture.

INTENDED USE

BacterPlate™ Columbia Agar is a highly nutritive medium used for the growth and isolation of a large variety of microorganisms, particularly very fastidious bacteria: streptococci and pneumococci in animal samples. When blood, selective agents or growth accelerators are added, it becomes possible to prepare a wide variety of media adapted to specific uses.
The packaging with semi-permeable Cellophane film helps balance the humidity of the environment during storage.

PRINCIPLES

Peptones included in the composition of the medium favor the excellent growth of colonies.
Yeast extract is a source of vitamin B complex.
Starch is a detoxifying agent and also an energy source.
Defibrinated sheep blood, which can be added to the medium, favors the detection of hemolytic reactions and supplies X factor (heme) required for the growth of a large number of bacteria, but lacks V factor (nicotinamide adenine dinucleotide) due to the presence of an NADase, which destroys any NAD present. Haemophilus influenzae, which requires both X and V factors, does not grow on agar containing ordinary blood.
The following media can be prepared with Columbia base :
- Blood agar: By adding 5 or 10% sterile sheep blood after autoclaving and cooling, the medium is suitable for the growth of Streptococcus, Pneumococcus, Staphylococcus, Listeria and Erysipelothrix. It can be made selective by adding colistin and nalidixic acid to preclude the development of Gram-negative bacteria and Bacillus.
- Chocolate agar: By adding 10% sheep or horse blood to sterile Colombia Agar and heating to 70°C for 5 minutes until a chocolate color develops, an excellent medium is obtained for growth of Haemophilus, Neisseria, Taylorella or Campylobacter.
- Base media without enrichment: Columbia Agar can be used to grow Brucella abortus, Yersinia pestis and Clostridium perfringens, as well as all enterobacteria

Allow to warm to room temperature before inoculation, dry the plates in an incubator with the covers partially removed.
Inoculate in order to obtain isolated colonies.
Incubate at 37°C for 24 to 48 hours in optimal conditions for the culture of the inoculated germs

RESULTS

Observe the bacterial growth.

Beta hemolysis
- Streptococci belonging to Lancefield group A appear as small, grey colonies, translucid or opaque, surrounded by a zone of beta hemolysis. Other bacteria may present the same type of hemolysis: Listeria, hemolytic Staphylococci, Escherichia coli and Pseudomonas.
- Staphylococci appear as opaque, yellow-gold or white colonies, with or without type β hemolysis zones.
- Listeria present small zones of beta hemolysis.
- Bacillus cereus form a clear zone surrounding the colonies.
Alpha hemolysis
- Pneumococci appear as flat, shiny, grey and occasionally mucoid colonies surrounded by a zone of narrow, greenish hemolysis referred to as alpha hemolysis.
CAMP Factor
- Group B Streptococci produce an extracellular, thermoresistant substance (CAMP Factor) which provokes a triangle of total hemolysis in a zone of incomplete staphylococcal hemolysis, at the junction of the two cultures.

BacterLab ensures the quality of each product batch by testing with ATCC reference strains.