Submitted to: American Association of Avian Pathologists
Publication Type: Abstract only
Publication Acceptance Date: 2/15/2007
Publication Date: 7/16/2007
Citation: Bouldin, J.G., Morales, C., Olson, A.B., Gilmour, M.W. 2007. Discrimination Between Strains of Salmonella Enteritidis PT13 and PT13a by Comparative Genome Sequencing of the Virulence Plasmid. American Association of Avian Pathologists.p.4421. Interpretive Summary:
Technical Abstract: Salmonella Enteritidis (SE) is an important pathogen of poultry products and it appears to be increasing within broiler flocks. Subtyping of SE is commonly done by phage typing, plasmid profiling, genomic microarrays, pulsed field gel electrophoresis and other restriction-enzyme based fingerprinting methods. A series of subtyping methods applied to SE PT13 strains isolated from disparate geographical and sources within Canada did not achieve adequate discrimination. However, comparative genomic sequencing detected putative single nucleotide polymorphisms (SNPs) in the large virulence plasmid that discriminated PT13 isolates obtained from humans and from mung bean sprouts from PT13a phenotypic variants and from the reference PT4 sequence. When compared to genomic sequence, the SE virulence plasmid appears to have a lower evolutionary rate of change. Three virulence plasmid SNPs were reliable for distinguishing PT13 lineage strains, which have the Fels2 phage, from the PT4 lineage, which has ST64b.