KM0026 – Edwardsiella ictaluri Medium

//KM0026 – Edwardsiella ictaluri Medium

KM0026 – Edwardsiella ictaluri Medium

Edwardsiella ictaluri medium is a selective medium for the isolation of Edwardsiella spp. based on the formulation by Shotts et al. (1) Edwardsiella spp. may be differentiated from other microorganisms on this medium due to its colony morphology.

The peptones provide the required carbon, nitrogen and vitamins. Sodium chloride maintains the osmotic balance. Colistin and bile salts are selective agents to inhibit most Gram-negative and Gram- positive organisms. Mannitol is a fermentable carbohydrate and bromthymol blue is a pH indicator. Phenylalanine and ferric citrate are used to detect phenylalanine deaminase activity in Proteus spp. Agar is a solidifying agent.

Shotts et al. (1) noted Proteus spp. swarming can overgrow on a mixed cultured sample. Therefore, a selective supplement (LS0021) may be added to the medium to restrict Proteus spp. swarming

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

OrganismRef. No.Result
(prepared with LS0021 Supplement)
Edwardsiella ictaluriNCIMB 13272Growth, green colonies
Edwardsiella tardaNCIMB 2056Growth, green colonies
Serratia marcescensATCC 8100Growth, yellow/red colonies
Proteus mirabilisNCTC 10975Growth, brown colonies

Formula*

FORMULA*g/L
Peptones20
Phenylalanine1.25
Ferric citrate1.2
Sodium chloride5
Mannitol3.5
Bile salts1
Colistin0.01
Bromthymol blue0.03
Agar13
Total45

Preparation

Suspend 45g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Sterilise at 121°C for 15 minutes with frequent agitation. Cool to 45- 50°C. If required add two vials of PNPG (LS0021) at this point, mix well and aseptically dispense into appropriate sterile containers.