Product Code: HAL001
A dual chromogen medium for the isolation of Salmonellae from food and clinical samples (including Salmonella typhi and paratyphi).
Salmonella spp. can be differentiated from other members of the family Enterobacteriaceae by their ability to produce α-galactosidase in the absence of β-galactosidase. This medium, developed for the isolation of Salmonella spp. from food and clinical samples, utilises a dual chromogen system to visualise these enzyme activities. This medium will also detect Salmonella typhi and paratyphi.
The first substrate, CHE-β-Gal, is enzymatically cleaved by β-galactosidase producing organisms giving black colonies in the presence of iron. Most Enterobacteriaceae are β-galactosidase positive and these produce black colonies on HarlequinTM Salmonella ABC Medium. The second substrate, X-α-Gal, is hydrolysed by Salmonella spp. producing green colonies that are easily distinguished from the black or colourless colonies of other organisms. The medium is based on D.C.A Hynes and hence utilises sodium desoxycholate and sodium citrate as inhibitors. Isolation of Salmonella spp. by culture remains the most reliable method of detection. However, most media are highly non-specific and consequently place a heavy burden on the laboratory in terms of biochemical and serological confirmation of suspect colonies. With improved specificity, the ABC medium dramatically reduces the need for 'false positive' screening, saving labour and reducing consumable costs.
Manufactured under exclusive licence from Newcastle Upon Tyne Hospitals NHS Trust.