An economic and rapid diagnostic procedure for the detection of salmonella/shigella using the polyvalent salmonella phage O-1.

An easy, rapid and economic two-step procedure is described for the detection of Salmonella/Shigella. In the first step the susceptibility of suspected colonies for the phage O-1 of FELIX and CALLOW is tested. Positive cultures are serologically confirmed. The test is performed on Triple Sugar Iron Agar and lasts 4-6 hrs. Phage negative cultures which are lactose- and sucrose negative are tested for lysine decarboxylase and, if Shigella is possible (i.e. in human material on primary plates), for indol production and motility in a semisolid tryptophane agar. Of 22880 Salmonella straine 21977, i.e. 96.1% were phage-sensitive. Strains belonging to certain O-groups (OE) or species are lysed at a lower percentage. However, since they are lysine decarboxylase positive they are not lost and can be submitted to a serological examination.