A Multiplex PCR based Method for the Identification of common Clinical Serotypes of Salmonella enterica subspecies enterica

A multiplex PCR method has been developed to differentiate between the most common clinical serotypes of Salmonella enterica subsp. enterica encountered in Washington State and the USA in general. Six genetic loci from S. Typhimurium and four from S. Typhi were used to create an assay consisting of two five-plex PCR reactions. The assays gave reproducible results with 30 different serotypes that represent the most common clinical isolates of S. enterica subsp. enterica. Of these, 22 serotypes gave unique amplification patterns when compared with each other and the other 8 serotypes were grouped into four pairs. These were further resolved by two additional PCR reactions. We compared the data from PCR serotyping with conventional serotyping and found that PCR serotyping was nearly as discriminatory as the conventional serotyping. The results from a blind test screening 111 clinical isolates revealed that 97% were correctly identified using the multiplex PCR assay. The assay can be easily performed on multiple samples with final results in less than 5 hours and, in conjunction with PFGE, forms a very robust test method for the molecular subtyping of Salmonella enterica serovar enterica. 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32