Genomic Variation of Salmonella enterica Serovar Paratyphi B (Tartrate +) Isolates from Clinical and Zoonotic Specimens as Measured by PFGE and Fragment Analysis of Multiplex PCR Products

Authors: LEADER, B - WASHINGTON DEPT OF HEALTH; Frye, Jonathan; KIM, S - KOREAN CDC; RUSSELL, D - WASHINGTON DEPT OF HEALTH; Jackson, Charlene; McGlinchey, Beth; Cray, Paula; HU, J - WASHINGTON DEPT OF HEALTH; BOYLE, D - WASHINGTON DEPT OF HEALTH

Submitted to: American Society for Microbiology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 2/16/2007
Publication Date: 5/24/2007
Citation: Leader, B.T., Frye, J.G., Kim, S., Russell, D., Jackson, C.R., Mcglinchey, B., Cray, P.J., Hu, J., Boyle, D. 2007. Genomic Variation of Salmonella enterica Serovar Paratyphi B (Tartrate +) Isolates from Clinical and Zoonotic Specimens as Measured by PFGE and Fragment Analysis of Multiplex PCR Products. American Society for Microbiology Conference. 282/C(C-287):198.

Interpretive Summary:

Technical Abstract: Many serovars of Salmonella enterica are important human and animal gastrointestinal pathogens that can result in morbidity and mortality. We developed a simple, quick, and sensitive molecular assay using a 12 target multiplex PCR assay to serotype multiple samples. In developing this 1 day assay we observed that S. paratyphi B (tartrate +, formerly S. java) and S. paratyphi B (tartrate -) often generate the same amplicon profile. Further mass screening of significant serovars showed that their amplicon profiles did not vary. We explored the extent of variance within S. paratyphi B (tartrate +) genovars. We screened over 100 isolates from human and animal specimens from different continents. These were all non-clonal by their PFGE patterns with Xba1. Capillary fragment analysis rather than agarose electrophoresis was used to analyze the PCR amplicons to improve the assay and to make it a high throughput technique for serotyping. A further 3 unique amplicon profiles were generated from S. paratyphi B (tartrate +) isolates to make 5 different profiles in total. One matched the S. paratyphi B (tartrate -) specimens and the four other profiles were still unique in relation to profiles of the other top 28 serovars. Some of the Scottish clinical specimens generated a unique profile and two other profiles were identified only once. Comparison of the clusters created in a dendogram of the PFGE patterns with the amplicon profiles revealed that unique profiles exhibited by some of the Scottish samples made a distinct cluster and the two rare profiles were unique patterns within the dendogram. The other results from the clinical and animal specimens were composed of the two most common genovars with no correlation as to their origin. Our results illustrate the PCR assay is a highly sensitive and rapid assay as an alternative technique to serotyping and also that unique genovars for S. paratyphi B (tartrate +) exist in distinct geographical areas. The relevance of this is still unclear but ultimately the increased specificity of typing by genovar may allow better epidemiologic monitoring of traits such as virulence, drug resistance and host specificity/susceptibility.