Capable of detecting Salmonella species within 24 hours, modified semi-solid Rappaport Vassiliadis (MSRV) medium is one of a range of products from Lab M devoted to the detection and isolation of these organisms. The medium offers a simple and rapid means of detecting motile strains of Salmonella, even if they are outnumbered by competitive bacteria by a factor of 107.
Motile organisms spread through the semi-solid agar, with organisms other than salmonellas being inhibited by selective agents in the medium. Spreading growth following overnight incubation indicates that salmonellas may be present. This is confirmed if a paper disc containing polyvalent H antiserum has been included on the plate, and a zone of inhibition can be seen around it.
The presence of Salmonella species should be confirmed by subculture from the edge of the motility zone onto XLD and Brilliant Green agar before performing biochemical and serological tests. Polyvalent antisera to Salmonella species or use of a latex test may also be needed for confirmation.
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