Overview:
Campy CVA Agar (Cefoperazone, Vancomycin, Amphotericin B Agar) is a selective, enriched blood agar medium formulated for the primary isolation and cultivation of Campylobacter species, particularly thermophilic strains such as C. jejuni and C. coli, from human fecal specimens, rectal swabs, food, and environmental samples. Developed as an improvement over earlier formulations like Skirrow's medium, it uses a nutritionally rich base (often Brucella or casein peptone-based) supplemented with 5% defibrinated sheep blood for essential growth factors like hemin (X-factor) and NAD (V-factor), while incorporating the CVA antimicrobial blend to inhibit competing normal enteric flora (Gram-negative bacilli, Gram-positive bacteria, and yeasts). This combination enhances recovery rates by suppressing overgrowth from Proteus, Pseudomonas, and other contaminants under microaerophilic conditions (5% O?, 10% CO?, 85% N?) at 42�C for 48-72 hours. Colonies of C. jejuni appear as small (1-2 mm), flat, grayish-white, mucoid, and spreading with irregular edges, typically non-hemolytic.
Applications:
?? Primary isolation of Campylobacter jejuni and C. coli from clinical stool samples for diagnosis of campylobacteriosis (gastroenteritis)
?? Detection in food microbiology, including poultry, milk, and water per FDA-BAM and ISO 10272 standards
?? Environmental and veterinary surveillance for Campylobacter in animal feces, sewage, and contaminated sites
?? Subculture from enrichment broths (e.g., Preston or Campy-Thio) or transport media (e.g., Cary-Blair) for delayed processing
Key Features:
?? CVA antimicrobials (cefoperazone for Gram-negatives, vancomycin for Gram-positives, amphotericin B for fungi) provide superior selectivity over cephalothin-based media
?? Enriched with sheep blood for fastidious growth factors, supporting >90% recovery of stressed or low-count pathogens
?? Opaque, cherry-red appearance post-preparation; promotes characteristic mucoid, flat colonies under elevated temperature (42�C)
?? Validated for high specificity in CLSI, APHA, and ATCC protocols; inhibits E. coli and Enterococcus while allowing C. jejuni ATCC 33560 growth
?? Compatible with filtration methods or direct plating; optional hydrogen supplementation for non-thermophilic species
Composition (per liter):
Pancreatic Digest of Casein (Peptamin) � 20.0 g
Sodium Chloride (NaCl) � 5.0 g
Yeast Extract � 2.0 g
Dextrose � 1.0 g
Sodium Bisulfite � 0.1 g
Agar � 17.5 g
Defibrinated Sheep Blood � 50.0 mL
Cefoperazone � 0.02 g
Vancomycin � 0.01 g
Amphotericin B � 0.002 g
Final pH: 7.0 � 0.2 at 25�C
Preparation:
Suspend 39.5 g of the dehydrated base in 1 liter of purified/distilled water. Heat with frequent agitation and boil for 1 minute to dissolve completely (do not overheat). Autoclave at 121�C (15 psi) for 15 minutes. Cool to 45-50�C in a water bath. Aseptically add 50 mL sterile defibrinated sheep blood and the rehydrated CVA supplement (cefoperazone 20 mg, vancomycin 10 mg, amphotericin B 2 mg in 10 mL sterile water). Mix gently to avoid bubbles and pour into sterile Petri plates (20-25 mL per plate). Allow to solidify at room temperature and dry the surface briefly before use. The prepared medium should appear opaque, cherry-red, and free of precipitates.
Storage:
Dehydrated medium: Store in a tightly closed container at 2-30�C, protected from moisture, light, and humidity; stable until expiry date (typically 3 years).
Prepared plates: Store at 2-8�C in sealed plastic bags or containers; use within 2 weeks. Discard if dehydrated, hemolyzed, discolored, or contaminated.
?? For laboratory and research use only. Not for diagnostic procedures without proper validation. Not for human or veterinary consumption. Handle under biosafety level 2; use Universal Precautions as it contains animal-derived blood�wear gloves and eye protection. Autoclave all waste before disposal. Incubate in microaerophilic jars; suboptimal atmospheres (e.g., candle jars) may reduce recovery. Not ideal for non-thermophilic Campylobacter without adjusted conditions.3.7s