This new chromogenic detection method for Salmonella spp has recently been validated by Afnor, according to the ISO 16140 requirements, for food and animal feed samples (No BRD 07/11-12/05)
Bio-Rad has extended its range of culture media to include Rapid Salmonella.
With Rapid Salmonella, full results can be obtained within 48hr (the second enrichment can last longer than 6hr for more convenience).
Method: after overnight buffered peptone water pre-enrichment (18hr +/-2hr), followed by selective enrichment in Rappaport Vassiliadis Soy (RVS) broth with an incubation time between 6hr and 26hr, 10litres of the RVS broth are inoculated on the Rapid Salmonella chromogenic plating agar.
An alternative confirmation is also validated in the Rapid Salmonella protocol and gives results in 1hr.
The principle of the Rapid Salmonella medium relies on the demonstration of two enzymatic activities.
Salmonella spp takes the form of readily identified, typical magenta colonies (detection of C8 esterase).
Counter selection is used in Rapid Salmonella to reveal other bacteria with a different colour.
Rapid Salmonella can detect motile and non-motile Salmonella as well as lactose-positive Salmonella, including S Typhi and S Paratyphi.
Economical, and easy to use: two broths, one plate.
Fast: full results can be obtained within 48hr, alternative confirmation in one hour.
Highly sensitive: detection of lactose-positive and non-motile S Paratyphi and S Typhi.
Easy to read: magenta colonies are Salmonella spp.
Good specificity and selectivity.
Rapid Salmonella chromogenic plating agar is also of interest as a second selective medium in the ISO 6579 reference method.
