Silje Vermedal Høgh

Whole Genome Sequencing of Danish Staphylococcus argenteus Reveals a Genetically Diverse Collection with Clear Separation from Staphylococcus aureus

Staphylococcus argenteus (S. argenteus) is a newly identified Staphylococcus species that has been misidentified as Staphylococcus aureus (S. aureus) and is clinically relevant. We identified 25 S. argenteus genomes in our collection of whole genome sequenced S. aureus. These genomes were compared to publicly available genomes and a phylogeny revealed seven clusters corresponding to seven clonal complexes. The genome of S. argenteus was found to be different from the genome of S. aureus and a core genome analysis showed that ~33% of the total gene pool was shared between the two species, at 90% homology level. An assessment of mobile elements shows flow of SCCmec cassettes, plasmids, phages, and pathogenicity islands, between S. argenteus and S. aureus. This dataset emphasizes that S. argenteus and S. aureus are two separate species that share genetic material.

Need for species-specific detection for the diagnosis of amoebiasis in a non-endemic setting.

Abstract The diagnosis of amoebiasis caused by Entamoeba histolytica is traditionally based on microscopy. However, the specificity of this method may be questioned, especially in areas where infections by E. histolytica are rare. In the present study, a species-specific real-time PCR was used for the identification of the morphologically similar species E. histolytica and Entamoeba dispar. Out of 15 microscopy-positive stool samples, all were negative for E. histolytica and positive for E. dispar. In 2 cases, a suspicion of amoebic liver abscesses was confirmed by detection of E. histolytica DNA in stored sample material. Microscopy alone is clearly insufficient for the detection of E. histolytica in a setting where this parasite is rare. Microscopy-positive stool samples should be further tested by species-specific tests to distinguish E. histolytica from the non-pathogenic parasite E. dispar. On specific suspicion of amoebiasis, such as the suspicion of amoebic liver abscesses, species-specific tests can be applied even after storage.

Draft Genome Sequence of “Terrisporobacter othiniensis” Isolated from a Blood Culture from a Human Patient

ABSTRACT “Terrisporobacter othiniensis” (proposed species) was isolated from a blood culture. Genomic DNA was sequenced using a MiSeq benchtop sequencer (Illumina) and assembled using the SPAdes genome assembler. This resulted in a draft genome sequence comprising 3,980,019 bp in 167 contigs containing 3,449 coding sequences, 7 rRNAs, and 58 tRNAs.