Harlequin™ Chromogenic Agar for Salmonella Esterase (CASE)

Productcode: NCM1006A
Supplier: Neogen Europe ltd
Package size: 500 g

Product information

CASE is a selective chromogenic agar for the detection of Salmonella. It utilises a dual chromogenic system to differentiate between Salmonella and non-target organisms that grow on the agar.

The first chromogen is a target for esterase activity present in Salmonella species. Utilisation of this chromogen results in blue/green colonies. The second chromogen is a target for ß-glucosidase present in non-target organisms that are able to grow on the agar and also possess esterase activity. Utilisation of the second chromogen masks the utilisation of the first resulting in black colonies in non-Salmonella.

All other organisms are either inhibited or grow colourless on the agar. The media is able to detect non-motile Salmonella (S.Pullorum and S.Gallinarum) as well as monophasic variants (1,4,[5],12:i:-). The media is also able to detect serovars that present weak esterase activity (S.Dublin), and lactose positive strains (S.Arizonae).

Contact our specialist

For more information from Labema’s specialist. The specialist for this product is Iiris Ylöstalo.

Send request


Comparison of Four Chromogenic Media and Hektoen Agar for Detection and Presumptive Identification of Salmonella Strains in Human Stools
We compared the performance of four commercial chromogenic media—namely, ABC medium (Lab M. Ltd., Bury, United Kingdom), COMPASS Salmonella agar (Biokar Diagnostics, Beauvais, France), CHROMagar™ Salmonella agar (CHROMagar Company, Paris, France), and SM ID agar (bioMerieux, Marcy l’Etoile, France)— with conventional Hektoen medium. Nine hundred sixteen stool samples from inpatients at three hospitals were cultured, in parallel, on the five media, both by direct inoculation and after selective enrichment in selenite broth. The specificity of the four chromogenic media was better than 91% after incubation for 24 h (77.7% with Hektoen agar) and better than 84% after incubation for 48 h (74.8% with Hektoen agar). This higher specificity reduces the need for confirmatory tests, thereby cutting technical time and reagent requirements. Both COMPASS agar and CHROMagar™ Salmonella, which after simple additional tests showed close efficiencies (96 and 97%, respectively), can be recommended as single-plate media of choice for the detection and presumptive identification of salmonellae in stools.