Carnobacterium Selective Agar Base (CTAS Agar Base) | M1892

Carnobacterium Selective Agar Base (CTAS Agar Base) | M1892

Recommended for the detection of Carnobacterium species.

Composition

Ingredients: Gms / Litre

Casitose ▲ 10.000
Yeast extract 10.000
Sucrose 20.000
Polysorbate 80 (Tween 80) 1.000
Trisodium citrate dihydrate 15.000
Manganese sulphate tetrahydrate 4.000
Dipotassium hydrogen phosphate 2.000
Thallium (I) acetate 1.000
Nalidixic acid, sodium salt 0.040
Cresol red 0.004
Agar 15.000
Final pH ( at 25°C) 9.0±0.2

**Formula adjusted, standardized to suit performance parameters
▲ - Equivalent to Peptone from casein

Directions

Suspend 74.91 grams (the equivalent weight of dehydrated medium per litre) in 990 ml purified / distilled water. Heat to boiling
to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 45-50°C and add
10ml of 10% 2, 3, 5-Triphenyl Tetrazolium Chloride (TTC)(FD057). Mix well and pour into sterile Petri plates.
Principle And Interpretation
Carnobacterium species are Gram-positive rods belonging to the family Lactobacillaceae and are not considered as human
pathogens. It comprises of 11 species, of which only two of these, Carnobacterium divergens and Carnobacterium
maltaromaticum, are isolated frequently from the environment and food (1). Carnobacterium species are commonly
isolated from a variety of foods like meats stored under anaerobic atmospheres at refrigeration temperatures, but the role of
these organisms in the spoilage of meat and meat products is yet to be determined.
Casitose serves as a source of nitrogen and amino acids. Yeast extract is the vitamin source. Sucrose and citrate is the
carbon source. Polysorbate 80 acts as an emulsifier. Dibasic potassium phosphate buffer the medium. Manganese sulfate helps
to stimulate growth of carnobacteria whereas Thallium acetate and nalidixic acid are used as inhibitory substance for
selective isolation of Carnobacterium spp.
Type of specimen
Clinical samples - Pus. Food and Dairy samples, Fish samples.
Specimen Collection and Handling:
For clinical samples follow appropriate techniques for handling specimens as per established guidelines (2,3).
For food and dairy samples, follow appropriate techniques for sample collection and processing as per guidelines (4,5,6).
After use, contaminated materials must be sterilized by autoclaving before discarding.
Warning and Precautions :
In Vitro diagnostic Use only. For professional use only. Read the label before opening the container. Wear protective
gloves/protective clothing/eye protection/ face protection. Follow good microbiological lab practices while handling
specimens and culture. Standard precautions as per established guidelines should be followed while handling clinical
specimens. Safety guidelines may be referred in individual safety data sheets.

Limitations :

1.Some species may show poor growth due to nutritional variations.
2.Further biochemical testing is required for complete identification

Performance and Evaluation
Performance of the medium is expected when used as per the direction on the label within the expiry period when stored at
recommended temperature.
Quality Control

Appearance
Light yellow to greenish yellow homogeneous free flowing powder
Gelling
Firm, comparable with 1.5% Agar gel.
Colour and Clarity of prepared medium
Red to purple-red coloured clear to slightly opalescent gel with precipitate forms in Petri plates.
Reaction
Reaction of 7.5% w/v aqueous solution at 25°C. pH : 9.0±0.2
pH
8.80-9.20
Cultural Response
Cultural characteristics observed after an incubation at 35-37°C for 18-24 hours or longer.(with 5% CO2)

Storage and Shelf Life
Store between 10-30°C in a tightly closed container and the prepared medium at 2-8°C. Use before expiry date on the
label. On opening, product should be properly stored dry, after tightly capping the bottle in order to prevent lump
formation due to the hygroscopic nature of the product. Improper storage of the product may lead to lump formation.
Store in dry ventilated area protected from extremes of temperature and sources of ignition. Seal the container
tightly after use.Product performance is best if used within stated expiry period.
Disposal
User must ensure safe disposal by autoclaving and/or incineration of used or unusable preparations of this product. Follow
established laboratory procedures in disposing of infectious materials and material that comes into contact with clinical
sample must be decontaminated and disposed of in accordance with current laboratory techniques (2,3).
Reference
1. Leisner, J. J., Groth Laursen, B., Prevost, H., Drider, D. & Dalgaard, P. (2007). Carnobacterium: positive and negative
effects in the environment and in foods. FEMS Microbiol Rev 31, 592–613.
2. Isenberg, H.D. Clinical Microbiology Procedures Handbook. 2nd Edition.
3. Jorgensen, J.H., Pfaller, M.A., Carroll, K.C., Funke, G., Landry, M.L., Richter, S.S and Warnock., D.W. (2015)
Manual of Clinical Microbiology, 11th Edition. Vol. 1.
4. American Public Health Association, Standard Methods for the Examination of Dairy Products, 1978, 14th Ed.,
Washington D.C.
5. Salfinger Y., and Tortorello M.L. Fifth (Ed.), 2015, Compendium of Methods for the Microbiological Examination of
Foods, 5th Ed., American Public Health Association, Washington, D.C.
6. Wehr H. M. and Frank J. H., 2004, Standard Methods for the Microbiological Examination of Dairy Products, 17th Ed.,
APHA Inc., Washington, D.C.