Overview:
Bolton Selective Enrichment Broth is the official international reference medium for the selective enrichment of thermotolerant Campylobacter spp. (especially C. jejuni, C. coli, C. lari, C. upsaliensis) from foods, animal faeces, and environmental samples. It is the mandatory enrichment broth in ISO 10272-1:2017, FDA-BAM Chapter 7, and USDA-FSIS methods. The combination of high nutrient level, haematinised blood, and four antibiotics provides excellent recovery of stressed and low-level Campylobacter.
Applications:
Detection of Campylobacter in poultry, meat, milk, and ready-to-eat foods
Official method ISO 10272-1 (all parts), FDA-BAM, USDA-FSIS
Clinical and veterinary samples when high background flora is present
Key Features:
Haematinised blood + pyruvate ? resuscitation of injured cells
Four antibiotics ? strong suppression of competing flora
Microaerobic incubation at 41.5 �C ? optimal for thermotolerant Campylobacter
Composition (per liter � Base only):
Meat Peptone 10.0 g
Lactalbumin Hydrolysate 5.0 g
Yeast Extract 5.0 g
Sodium Chloride 5.0 g
Sodium Pyruvate 0.5 g
Sodium Metabisulfite 0.5 g
?-Ketoglutaric Acid 1.0 g
Haematinised Blood (or lysed horse blood) 50 mL
Final pH: 7.4 � 0.2 at 25 �C
Antibiotic Supplement (Bolton Selective Supplement � added after reconstitution):
Vancomycin 20 mg
Trimethoprim 20 mg
Cefoperazone 20 mg
Amphotericin B (or Cycloheximide) 10 mg
Preparation:
Suspend 27.0 g Bolton Broth Base in 950 mL purified water.
Autoclave at 121 �C for 15 min.
Cool to 45�50 �C.
Add 50 mL sterile lysed horse blood (or reconstituted blood supplement).
Aseptically add reconstituted Bolton Selective Supplement (one vial per 500 mL or 1 L).
Mix gently and dispense 10�25 mL into sterile tubes/flasks.
Incubation:
37 �C for 4�6 h (pre-enrichment) ? 41.5 �C for 40�44 h total
Microaerobic atmosphere (5 % O?, 10 % CO?, 85 % N?)
Subculture:
After 44 � 4 h, subculture onto mCCDA or Karmali Agar.
Storage:
Dehydrated base: cool, dry place below 30 �C
Complete prepared broth: 2�8 �C, use within 24 h (blood-containing)
For laboratory food, clinical, and veterinary microbiology use only.
Official reference: ISO 10272-1:2017, Hunt et al. (1998), Bolton & Robertson (1982).