Park and Sanders Enrichment Broth Base

Park and Sanders Enrichment Broth Base is recommended for selective enumeration of thermotolerant Campylobacter species from foods.

Composition

Final pH (at 25°C): 7.0±0.2

**Formula adjusted, standardized to suit performance parameters

Directions

Suspend 28.35 grams in 940 ml distilled water. Heat if necessary to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 40-45°C and aseptically add 50 ml of sterile defibrinated lysed horse blood and reconstituted contents of 1 vial of Park and Sanders Selective Supplement 1 (FD104). Mix well. Inoculate with food samples and incubate at 31 to 32°C (to recover injured cells) for 4 hours.

Aseptically add reconstituted contents of 1 vial of Park and Sanders Selective Supplement II (FD105) and incubate at 37°C for 2 hours, then at 42°C under a microaerobic atmosphere for additional 40 to 42 hours with agitation at 100 rpm.

Principle And Interpretation

Park and Sanders Broth was formulated by Park and Sanders for enrichment of Campylobacter species (1). Park and Sanders Enrichment Broth is recommended by APHA (2), for selective enumeration of thermotolerant Campylobacter species in food and animal feed.

Casein enzymic hydrolysate, peptic digest of animal tissue, yeast extract provide nitrogenous compounds, carbon, sulphur, vitamins and trace elements. Dextrose is the energy source. Campylobacter species are microaerophilic. Sodium pyruvate helps for aerotolerance. Sodium sulphite helps in survival of the organism in higher nitrogen atmosphere (3). Supplementation of base with antibacterial and antifungal agents as described by Park and Sanders (1) provides for a markedly reduced growth of normal enteric bacteria and improved recovery of Campylobacter species.

After addition of blood and Sanders Selective Supplement I (FD104), the medium is incubated at 31 to 32°C for 4 hours for the recovery of injured cells. The resuscitation and enrichment of culture must be performed in a microaerobic environment. The organism is sensitive to oxygen and storage at room temperature. The food sample should be stored in an oxygen-free environment with 0.01% sodium bisulfite and held under refrigeration. Under these conditions the organism will survive 10 times longer than when the same strain is held in a bisulfite-free medium exposed to air at 25°C (3). Some strains of normal enteric organisms may be encountered that are not inhibited or only partially inhibited on this medium.

Quality Control

Appearance: Light yellow to beige homogeneous free flowing powder

Colour and Clarity of prepared medium: Basal medium - Light yellow coloured clear solution. After addition of 5% w/v sterile defibrinated lysed horse blood - Cherry red coloured opalescent solution in tubes

Reaction: Reaction of 2.84% aqueous solution at 25°C. pH: 7.0±0.2

pH: 6.80-7.20

Cultural Response

M1185: Cultural characteristics observed with added 5% defibrinated lysed horse blood along with FD104 and FD105, after an incubation at 42°C for 48 hours under microaerobic atmosphere.

Storage and Shelf Life

Store below 30°C in tightly closed container and the prepared medium at 2 - 8°C. Use before expiry date on the label.

Reference

1. Park C.E. and Sanders G.W., 1989, Abstr. 5th International Workshop on Campylobacter Infections, Puerto Vallarta, Mexico.
2. Downes F. P. and Ito K., (Eds.), 2001, Compendium of Methods for the Microbiological Examination of Foods, 4th Ed., APHA, Washington, D.C.
3. Koidis P. and Doyle M.P., 1983, Eur. J. Clin. Microbiol., 2:384.