Location: Meat Safety & Quality ResearchTitle: Mobilome differences between Salmonella enterica serovars Anatum and Typhimurium isolated from cattle and humans and potential impact on virulence Author
|Bono, James - Jim|
|Smith, Timothy - Tim|
Submitted to: Annual Wind River Conference on Procaryotic Biology
Publication Type: Abstract Only
Publication Acceptance Date: 1/29/2016
Publication Date: 6/5/2016
Citation: Nguyen, S.V., Bono, J.L., Smith, T.P.L., Kelley, C.M., Wang, R., Harhay, G.P., Harhay, D.M. 2016. Mobilome differences between Salmonella enterica serovars Anatum and Typhimurium isolated from cattle and humans and potential impact on virulence. [Abstract] In proceedings: 60th Wind River Conference on Procaryotic Biology, 2016 June 1-5. Estes Park, Colorado. p. 67.
Technical Abstract: Salmonella enterica subsp. enterica is an important group of pathogens capable of inhabiting a range of niches and hosts with varying degrees of impact, from commensal colonization to invasive infection. Recent outbreaks of multi-drug resistant S. enterica, attributed to consumption of contaminated ground beef, have led to increased scrutiny of the presence of these pathogens in red meat. To date there has been limited comparative genomics research examining the virulence determinants that exists among serotypes of S. enterica associated with cattle. Such comparisons are necessary to understand disease etiology in cattle and humans. For S. enterica genomic comparisons, we present the complete genome sequences of 24 S. enterica isolates of serotypes Anatum (BA, bovine n=7; HA, human n=5) and Typhimurium (BT, bovine; HT, human n=6 each), isolated from healthy cattle or clinically infected humans. For all isolates, genomes were sequenced with single molecule real time technology and subsequently closed (HGAP3 or Celera 7.3). All circularized genomes and plasmids were annotated using a local instance of Do-It-Yourself Annotator (DIYA). Using the EDGAR comparative genomics system, phylogenetic trees were constructed and core-genome and pan-genome analyses performed between the different serotypes. Core and pan-genome values for Anatum were 4302 and 4969 ORFs, while those for Typhimurium were 4362 and 5347 ORFs respectively. Comparisons of core-genomes revealed that many of the non-orthologous gene sets observed are associated with the mobilome. Specifically phages GIFSY-1 and GIFSY-2 were found predominantly in Typhimurium, while transposon IS903 was found in several strains of Anatum only. Analysis of the BA and HT core-genomes revealed that 4118 genes were shared while 213 and 304 were unique to BA and HT, respectively. Genes unique to the HT core and possibly important for virulence, include retrons, methyltransferases, fimbrial operons, secreted effectors, and phosphotransferase systems. The results of these analyses and implications for differences in virulence potential within these serovars will be discussed.