Submitted to: Scientific and Technical Review
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 29, 2008
Publication Date: March 1, 2008
Citation: Guard, J.G. 2008. Evolutionary trends in two strains of Salmonella enterica subsp. I serovar Enteritidis PT13a that vary in virulence potential: Version 5 NCBI database. National Center for Biotechnology Information (NCBI)Available:http://www.ncbi.nlm.nih.gov/Salmonella_SNPs.html Interpretive Summary: No summary required
Technical Abstract: Salmonella enterica subsp. I serovar Enteritidis (S. Enteritidis) is the world's leading cause of salmonellosis. Eggs contaminated by apparently healthy hens and that have been improperly cooked can result in illness in humans who consume them. Although the incidence of this pathogen within the United States has not been as high as it has been in Europe, current estimates from the Centers for Disease Control and from the USDA-Food Safety Inspection Service respectively suggest that this pathogen has begun to contaminate broilers in the States (1). To investigate the genetic basis for the ability of a bacterium to contaminate eggs as well as to have other unique virulence characteristics, the genomes of two monomorphic strains of S. Enteritidis PT13a that were descended over ten years from a single parent were subjected to virtual subtraction hybridization against dimorphic S. Enteritidis PT4 (3). Direct comparison of the closely related genomes was possible by using the genome database for S. Enteritidis PT4 NCTC 13349 to generate overlapping sets of primers (Nimblegen, Inc.) that were capable of detecting single nucleotide polymorphisms (SNPs). The database of the S. Enteritidis PT4 reference genome is from the Pathogen Sequencing Group at the Sanger Institute and can be obtained from http://www.sanger.ac.uk/Projects/Salmonella/. Version 5 lists an additional 69 confirmed polymorphisms, which brings the total to 286 chromosomal polymorphisms detected at an intermediate or high stringency level of analysis; in addition, 178 putative polymorphisms require further analysis for confirmation that they differ between strains (Table S1).