Campylobacter Blood Free Selective Medium

(Modified CCDA-Improved)

LAB 112

Description

A blood free medium which will support the growth of most enteric campylobacters. The selective cocktail X112 (X212) makes the medium selective for C. jejuni. C. coli and C. laridis when incubated at 37˚C. With this product incubation at 42˚C is no longer necessary and higher recovery rates have been reported at 37˚C than at 42˚C.

The supplement X112 (X212) consists of cefoperazone and amphotericin and is superior to the selective cocktails of Skirrow, Butzler and Blazer-Wang all of which contain antibiotics shown to be inhibitors to C. coli. The colonial morphologies of Campylobacter spp. on this medium are distinctive.

Method for reconstitution

Weigh 45.5 grams of powder, disperse in 1 litre of deionised water and allow to soak for 10 minutes. Swirl to mix, then sterilise by autoclaving at 121˚C for 15 minutes. Cool to 47˚C then add 2 vials of X112 supplement, mix well and pour into Petri dishes. Continuously mix whilst pouring to prevent the charcoal settling.

Appearance: Black agar.

pH: 7.4 ± 0.2

Minimum Q.C. organisms: C. jejuni

E. coli (inhibition) NCIMB 50034 Candida albicans (inhibition) NCIMB 50010

Storage of Prepared Medium: Plates - up to 7 days at 2-8˚C in the dark.

Inoculation: C. jejuni, C. coli. C. laridis surface streaking to single colonies.

Incubation: 37˚C for 48 hours in an atmosphere of 5% oxygen, 10% carbon dioxide and 85% nitrogen. C. cinaedi and C. fennelliae require up to 7 days.