Clostridium Difficile Agar (Base)

Clostridium difficile Agar (Base)

• Used in the selective isolation and cultivation of Clostridium difficile
• To be prepared with the addition of blood, cycloserine, and cefoxitin
  
• pH: 7.4
• Dehydrated Appearance: light beige, homogeneous powder
• Prepared Appearance: light to medium amber broth
• Soluble in boiling water
• Working Concentration: 69.1g/L

Clostridium difficile agar base composition (g/L):

• Proteose peptone - 40g
• Fructose - 6.0g
• Disodium phosphate - 5.0g
• Sodium chloride - 2.0g
• Potassium phosphate, monobasic - 1.0g
• Magnesium sulfate, heptahydrate - 0.1g
• Agar - 15.0g

Final pH 7.4 ± 0.2 @ 25°C

Direction to use: Add 69.1g of Clostridium difficile agar base to 920ml of purified water. Mix thorougly and autoclave at 121°C for 15 minutes. Cool to 45-50ºC and aseptically add Clostridium Difficile selective Supplement (see below), previously reconstituted in 10 ml of sterile distilled water and 70ml sterile defibrinated horse blood. Mix thoroughly but gently to avoid bubble formation and dispense into Petri dishes or sterile tubes.

Clostridium difficile selective supplement (per 10ml):

• D-Cycloserine - 500mg
• Cefoxitin - 16.0mg