Submitted to: ASM Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/20/2015
Publication Date: 9/25/2015
Citation: Haley, B.J., Van Kessel, J.S., Karns, J.S. 2015. Salmonella enterica serovar Kentucky isolates from dairy cows and poultry demonstrate different evolutionary histories and host-specific polymorphisms. Meeting Abstract. ASM Conference, Washington, DC. September 24-27, 2015.
Technical Abstract: Salmonella enterica subsp. enterica serovar Kentucky is commonly isolated from dairy cows and poultry in the United States. Although it is not among the most frequently isolated serovars from cases of human salmonellosis, its high prevalence in livestock and poultry indicate it is a potential public health threat, particularly in light of the global spread of multi-drug resistant S. Kentucky ST198. To investigate genomic differences between S. Kentucky isolated from dairy farms and poultry operations, the genomes of 41 S. Kentucky ST152 isolates recovered from dairy cows and four S. Kentucky ST152 isolates recovered from poultry were sequenced using an Illumina NextSeq 500. Publically available S. Kentucky data were retrieved from the NCBI Sequence Read Archive and phylogenies were inferred after SNPs were detected using both ParSNP and the CFSAN SNPfinder. Phylogenetic inference demonstrated that S. Kentucky ST152 isolates from poultry evolved from those frequently recovered from dairy cows. The S. Kentucky genomes in the clades dominated by cow isolates are differentiated from those in the clade dominated by poultry isolates by nine conserved single nucleotide polymorphisms. A significant number of the SNPs were located in open reading frames identified as iron-scavenging genes suggesting these differences are at least partly responsible for the host-specificity. Interestingly, among the isolates, there was no evidence of mixing of cow and poultry S. Kentucky. However, there was one isolate that appeared as intermediate and was rooted near the most recent common ancestor. Within the cow-specific clade, isolates were, in general, clustered by geography, however some geographical mixing was observed. Results of this analysis indicate a geographical location and source (cow or poultry) could be inferred from the genome sequences of S. Kentucky.