Preston Modification
Campy Selective Agar Base (Powder) is highly nutritive medium for the selective isolation of Campylobacter jejuni and Campylobacter coli. Many experts consider Campylobacter to be the leading cause of enteric illness in the US (1). Campylobacter spp. pathogens are highly infective and transmitted by contaminated food or water. Campy Selective Agar Base (Powder) is based on the formulation described by Bolton and Robertson (2). This formula was developed to isolate Campylobacter spp. from human, animal and environmental specimens. The Preston formulation demonstrated improved recovery and selectivity of Campylobacter spp. in comparative studies with other selective media (Skirrow, Butzler, Blaser and Campy-Blood Agar). Enzymatic Digest of Animal Tissue and Enzymatic Digest of Casein are the nitrogen and vitamin source in this medium. Sodium chloride provides the osmotic environment. Agar is the solidifying agent. Antimicrobics are added to suppress normal enteric flora, and enhance the growth of Campylobacter spp. The addition of 5% lysed horse blood provides essential growth factors.
Quality Control Cultural Response
Medium was prepared according to label directions and inoculated with the organisms listed below. Campylobacter sp. test strains were incubated at 42 ± 1ºC in a microaerophilic atmosphere (consisting of ~5-6% oxygen, 3-10% carbon dioxide, 84-85% nitrogen). All other test strains were incubated at 42 ± 1ºC in an aerobic atmosphere.
Campylobacter coli (ATCC 33559)
Growth (Innoculum: 10-300cfu): Fair to excellent recovery
Campylobacter jejuni (ATCC 29428)
Growth (Innoculum: 10-300cfu): Fair to excellent recovery
Campylobacter jejuni (ATCC 33291)
Growth (Innoculum: 10-300cfu): Fair to excellent recovery
Candida albicans (ATCC 10231)
Growth (Innoculum: ~1000cfu): Markedly suppressed
Enterococcus faecalis (ATCC 29212)
Growth (Innoculum: ~1000cfu): Inhibited
Proteus mirabilis (ATCC 12453)
Growth (Innoculum: ~1000cfu): Inhibited
Notes
Campylobacter colonies are round to irregular with smooth edges. They may have translucent, white colonies to spreading, flat, transparent growth. Some strains appear tan or slightly pink. Normal enteric flora are completely to markedly inhibited. Typically, Campylobacter spp. are oxidase positive and catalase positive. For complete identification of species and biotype, refer to the appropriate procedures for biochemical reactions (1,4). Due to nutritional variation, some strains may be encountered that grow poorly or fail to grow on this medium.
The antibiotic supplement is not necessary for the recovery of pure isolates of Campylobacter. It is necessary for recovering Campylobacter from mixed flora. This supplement is for the selective isolation of C. jejuni and C. coli. The C. fetus species may not be recovered on C1038 when supplemented with these antiboiotics. Yeasts, gram positive and gram negative "nuisance" strains will be inhibited when the medium is supplemented with these antiboiotics.
Appearance: Light beige, homogeneous, free flowing powder. Solubility: Clear, amber, complete pH (1.5%): 7.5 ± 0.2
Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
Directions per Liter
Dissolve 37 grams per liter of distilled/deionized (DDI) water. Heat with stirring. Boil 1 minute until completely solubilized. Adjust pH as necessary. Dispense into appropriate containers. Loosen caps or cover with foil. Autoclave for 15 minutes at 121ºC (15psi). Aseptically add 5% lysed horse blood and 10ml of filter sterilized aqueous solution of antimicrobials.
Storage and Stability
Store powdered media at RT. Stable for 12 months after receipt. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept at 4°C and used within a short period of time.
Components
Enzymatic Digest of Animal Tissue | 10g |
Enzymatic Digest of Casein | 10g |
Sodium chloride | 5g |
Agar | 12g |