Comparison of three stool-processing methods for detection of Salmonella serogroups B, C2, and D by PCR

Three different stool sample-processing methods (centrifugation, immunomagnetic separation, and selective enrichment cultivation) for the identification of Salmonella serogroups by PCR were studied. The corresponding sensitivities in an ethidium bromide stained-agarose gel were 10(5), 10(3), and 10 bacteria, respectively. The PCR assay with overnight enrichment performed as well as, or even better than, the conventional culture technique. Of 485 clinical stool samples, PCR correctly identified all 230 culture-positive samples as well as mixed Salmonella infections in four cases.