Phylogenetic analysis of Shewanella spp. isolated from fish.

Different species of Shewanella spp. widely inhabit freshwater and marine environments. Some of them are opportunistic fish pathogens. The application of high-throughput sequencing enabled the characterization and taxonomic reclassification of many Shewanella spp. species. Still, some strains collected from fish need to be better recognized. The aim of the present study was to classify and determine the phylogenetic relationships of Shewanella spp. collected from fish. The complete genomes of 94 strains of Shewanella spp. from different fish species were sequenced using Illumina platform (MiSeq). The 16S rRNA gene, genomic features and whole-genome relationships of those bacteria were comprehensively analysed in comparison to reference strains. Whole-genome analysis showed that the tested Shewanella spp. strains were clustered into six groups similar to reference strains of S. xiamenensis, S. oneidensis, S. glacialipiscicola, S. hafniensis, S. baltica and S. oncorhynchi. Our study indicates that the whole-genome sequence analysis enabled taxonomic classification and assessment of the diversity of the Shewanella spp. strains, as opposed to recently the gold standard method of 16S rRNA amplicon sequencing. The high genetic diversity and low similarity to the reference genome of S. oneidensis indicate that the group of strains may be a subspecies or even new species. Furthermore, we showed that the most frequent Shewanella spp. species occurring in freshwater fish in our study is the recently described species S. oncorhynchi.

Draft genome sequences data of four Salmonella enterica subsp. enterica serovar Dublin archival strains originating from animals in Poland, 1956 - 1957.

Salmonella enterica subsp. enterica serovar Dublin (S. Dublin) is a zoonotic pathogen causing infections in animals, especially in cattle. In this study, we report draft genome sequences of four S. Dublin isolated between 1956 and 1957 from cattle and fox in Poland. Whole genome sequencing was performed on the Illumina platform and the data is available at National Center for Biotechnology Information under the BioProject accession number PRJNA865912. In order to better understand the genetic basis of epidemiology of S. Dublin infection, the obtained sequences were analyzed using the tools which are available at Center of Genomic Epidemiology (https://www.genomicepidemiology.org/) including core genome multilocus sequence typing (cgMLST) and core genome single nucleotide polymorphisms (cgSNPs).