Rapid detection of Salmonella in field samples by nested polymerase chain reaction

A simple and universal protocol for the rapid detection of Salmonella spp. in various samples using nested polymerase chain reaction (PCR) was develop ed. The protocol takes advantage of the rapid purification and concentratio n of Salmonella by centrifugation onto a layer of 60% sucrose solution. DNA was released by treatment with proteinase K and Triton X-100. Even without pre-enrichment, the detection limit for the nested PCR was 10(5) CFU g(-1) of faeces. After pre-enrichment, it was possible to detect Salmonella in f aeces where their original concentration was approximately 10(2) CFU g(-1) of faeces and in meat samples, it was possible to detect Salmonella in samp les where their original concentration was less than 10 cells g(-1) of minc ed meat.