Overview:
Campylobacter Agar Base (also known as Campy Agar Base) is a nutritionally rich, selective solid medium designed for the primary isolation and enumeration of Campylobacter species, particularly thermophilic strains like C. jejuni and C. coli, from clinical fecal specimens, food, dairy, and environmental samples. Originally based on Skirrow's formulation (1977) using a blood agar base with antibiotics, it was refined by Blaser et al. (1978) and others to enhance selectivity against competing enteric flora while providing essential growth factors such as X-factor from blood. The base medium supplies peptides, vitamins, and minerals, but requires supplementation with 5-10% lysed horse or sheep blood and antimicrobial agents (e.g., Skirrow or Blaser-Wang supplements containing vancomycin, polymyxin B, trimethoprim, and optionally cephalothin or amphotericin B) for optimal performance under microaerophilic conditions (5% O?, 10% CO?). Colonies of C. jejuni typically appear flat, grayish, non-hemolytic, and spreading (mucoid) after 24-48 hours at 42�C.
Applications:
?? Selective isolation of Campylobacter jejuni and C. coli from human and animal fecal samples in clinical diagnostics for gastroenteritis
?? Microbiological examination of poultry, meat, milk, and water for foodborne pathogen detection per FDA and ISO standards
?? Environmental monitoring of Campylobacter in sewage, soil, and animal husbandry settings
?? Enrichment and subculture from transport media like Cary-Blair for delayed processing
Key Features:
?? Enriched peptone and yeast extract base supports fastidious microaerophiles with essential amino acids, vitamins, and trace elements
?? Compatible with multiple antibiotic supplements for broad-spectrum inhibition of Gram-negative and fungal contaminants
?? Promotes characteristic colony morphology (gray, flat, spreading) and motility under microaerophilic incubation at 37-42�C
?? Validated for high recovery rates (>80%) of ATCC strains like C. jejuni ATCC 29428 in APHA, EU, and CLSI protocols
?? Blood supplementation provides hemin (X-factor) and neutralizes toxic oxygen radicals for stressed cells
Composition (per liter):
Proteose Peptone � 15.0 g
HL Digest (Lactic Acid Hydrolysate of Casein or Liver Digest) � 2.5 g
Yeast Extract � 5.0 g
Sodium Chloride (NaCl) � 5.0 g
Agar � 12.0 g
Final pH: 7.4 � 0.2 at 25�C
Preparation:
Suspend 39.5 g of the dehydrated medium in 1 liter of purified/distilled water. Heat with gentle agitation to boiling until completely dissolved (do not overheat to avoid caramelization). Autoclave at 121�C (15 psi) for 15 minutes. Cool to 45-50�C in a water bath. Aseptically add 50-70 ml sterile lysed horse blood or 100 ml sterile defibrinated sheep blood, plus the rehydrated contents of one vial of selective supplement (e.g., Skirrow: vancomycin 10 mg, polymyxin B 2,500 IU, trimethoprim 5 mg; or Blaser-Wang variant). Mix thoroughly and pour into sterile Petri plates (20-25 ml per plate). Allow to solidify and dry surface before use. Prepared plates should appear cherry red and opaque.
Storage:
Dehydrated medium: Store in a tightly closed container at 10�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 1-2 weeks. Discard if dehydrated, contaminated, or if blood shows hemolysis/lysis.
?? For laboratory and research use only. Not for diagnostic procedures without proper validation. Not for human or veterinary consumption. Handle under biosafety level 2 conditions; autoclave waste before disposal. Avoid exposure to air post-preparation to prevent drying; incubate in anaerobic jars or microaerophilic chambers. Not suitable for non-thermophilic Campylobacter without adjusted incubation.