- Cetrimide agar (BAM Media – M37)
- Cetrimide means Cetryl trymethyl ammonium Bromide is a selective agent.
- This media enhance the Pseudomonas pigments such as pyocyanin and flurorescein.
- Which show a characteristic blue-green and yellow-green colour, respectively.
- Cetrimide agar is the selective isolation of the gram negative bacterium, Pseudomonas aeruginosa.
Compositions Gram/liter
Enzyamatic digest of
Gelatin------------------------------------20g
Magnisium
chloride-----------------------------------------------1.4g
Potasium
sulfate----------------------------------------------------10g
Cetrimide-------------------------------------------------------------0.3g
Agar------------------------------------------------------------------13g
- Finally add supplement Glycerol 10 ml/1liter.
- Glycerol source of carbon.
- Enzymatic digest of gelatin –source of nitrogen, vitamins and less carbon.
- Magnesium chloride and potassium sulfate ---- enhance the pyocynin microorganisum
- Cetrimide ------------Quaternary ammonium cat ionic detergent causing nitrogen and phosphorus to be release from bacterial cells.
- Megnisium ions also neutralize the EDTA.
- 1 vial rehydrated Nalidixic selective supplement add mix well of 1000 ml of medium.
- Nalidixic selective supplement is an antibiotic supplement. 1 vial = 15 mg
- Colonies -------------yellow(media color) to change -------------------green to blue-green colonies.
- CA- colonies may appers pigmented blue, blue green or non-pigmented.
- Colonies exhibitiry flurosence at 250 nm, (under UV light).
Nalididixic selective suppliments
·
An antibiotic supplement
·
Isolation of
Pseudomonas aeruginosa
·
Rehydrated vial ( 15 mg) with 5 ml of sterile
distilled water.
·
Mix well aseptically add to 1000 ml of sterile,
molten, cooled (45-500C) Cetrimide
ager Base.
