Rappaport-Vassiliadis (MSRV) Medium Semi-Solid

Rappaport-Vassiliadis (MSRV) Medium Semi-Solid is a modification of Rappaport-Vassiliadis Soy Broth for detecting motile Salmonella spp. in faeces and food products.[1]The original research on MSRV Medium revealed a semi-solid could be used as a rapid and sensitive test for isolating motile Salmonella spp.

from food products following pre-enrichment or selective enrichment.[2]The semi-solid medium allows motility to be detected as halos of turbid growth around the original point of inoculation.

The peptones are to provide vitamins, nutrients and nitrogen to encourage growth of Salmonella spp.The salt maintains the osmotic balance and potassium dihydrogen phosphate is a buffer for stabilising the pH of the medium.

Malachite green is included as a selective agent that inhibits Gram-positive organisms and some Gram-negative organisms.References(1) ISO 6579-1:2017.

Microbiology of the food chain Horizontal method for the detection, enumeration and serotyping of Salmonella Part 1: Detection of Salmonella spp.(2) De Smedt J.M., Bolderdikj R., Rappold H. and Lautenschlaeger D. 1986. Rapid Salmonella Detection in Foods by Motility Enrichment on a Modified Semi-Solid Rappaport-Vassiliadis Medium. J. Food Prot. 49:510-514

Broth for detecting motile Salmonella spp. in faeces and food products.

Shelf Life (days): 1095 days

Dehydrated Medium Appearance: Fine Powder

Dehydrated Medium Colour: Beige – light blue

Dehydrated PH: 5.25±0.15

Prepared Medium Appearance: Semi-solid gel

Prepared Medium Colour: Turquoise blue

Prepared PH: 5.25±0.15

Formula g/L

Enzymatic digest of animal and plant tissue: 4.6

Acid hydrolysate of casein: 4.6

Sodium Chloride: 7.3

Potassium dihydrogen phosphate: 1.5

Magnesium chloride anhydrous: 10.9

Malachite green oxalate: 0.04

Agar: 2.7

Total: 31.64