Genotyping of Salmonella spp. by 16S-23S rRNA assay

ObjectiveTo develop a polymerase chain reaction-denaturing high performance liquid chromatography (PCR-dHPLC)genotyping method for genotyping of Salmonella spp.MethodsSpecific primers of 16S-23S rRNA intergenic spacer sequence(ITS)region were used to subtype Salmonella spp.The PCR amplification products of experimental strains were separated by dHPLC.The results of genotyping achieved through the differences between dHPLC peaks and were comparaed to the results obtained by serological typing and biochemical typing.ResultsTotally 89 Salmonella spp.strains were successfully genotyped into 12 dHPLC types(D type).All the Salmonella spp.strains had one same chromatographic peak,while other food-born pathogens showed no similar peak.DNA sequence analysis showed that the sequence was 600bp.The results indicate that the chromatographic peak is specific to Salmonella spp.Comparing the dHPLC genotyping results with those of serological typing and biochemical typing,we found dHPLC genotyping results were significantly differ from the serological typing results,while were consistent with that of the biochemical typing.ConclusionDHPLC is a novel,rapid,highly accurate,and cost-effective genotyping method for genotyping of Salmonella spp.