Modified Semi-Solid Rappaport-Vassiliadis (MSRV) Agar

Modified Semi-Solid Rappaport-Vassiliadis (MSRV) Agar is used with Novobiocin (NCM4040) for the rapid detection of motile Salmonella spp. and is not intended for use in the diagnosis of disease or other conditions in humans. MSRV was developed in 1986 by De Smedt, Bolderdijk and Rappold as a rapid means of Salmonella detection. The medium, based upon Rappaport Vassiliadis broth, is inoculated directly from the preenrichment medium, in the center of the plate. Motile organisms spread from the center in the semi-solid agar, but non-salmonellas are inhibited by the selective agents. After overnight incubation the use of polyvalent salmonella antisera or a latex kit can confirm the presence of a Salmonella. Alternatively, a paper disc wetted with polyvalent H antiserum can be placed 1/3 of the way from the edge of the dish, and will signal the presence of a Salmonella by inhibiting the mobility of the organism around the disc. Using this medium De Smedt and Bolderdijk have reported the possibility of detecting Salmonella in 24hrs (1987).