First chromogenic culture medium to simultaneously detect Salmonella and Shigella

Hardy Diagnostics, an ISO certified biomedical firm, is pleased to announce the release of HardyCHROM™ SS, a highly selective chromogenic medium recommended for use as a primary screening medium for the isolation and differentiation of Salmonella and Shigella spp. from stool cultures. These two pathogens can be easily distinguished from non-pathogenic enteric bacteria based on colony color. Differentiation of Salmonella and Shigella spp. from non-pathogenic bacteria is accomplished by three mechanisms: chromogenic reactions, carbohydrate fermentation, and hydrogen sulfide production. Shigella and non-H2S producing Salmonella spp. appear as turquoise colonies. H2S producing Salmonella will develop colonies with black centers.

HardyCHROM™ SS represents the first and only chromogenic culture medium that simultaneously detects both Salmonella and Shigella spp. while ruling out non-pathogenic enteric bacteria (both lactose and non-lactose-fermenting organisms). Most Proteus spp. do not produce black colonies (H2S) and do not produce a color change on this medium; and therefore are not confused with Salmonella and Shigella.

HardyCHROM™ SS provides superior differentiation of colonies, reduces the need for secondary testing of isolates, and thus results in less false-positive results.  HardyCHROM™ SS also allows the laboratory technologist to use fewer culture media plates when setting up stool cultures.