High intraspecies heterogeneity within Staphylococcus sciuri and rejection of its classification into S. sciuri...

Area of Science:

• Microbiology
• Taxonomy
• Bacterial Genetics

Background:

• The species *Staphylococcus sciuri* is currently divided into three subspecies: *S. sciuri* subsp. *sciuri*, *S. sciuri* subsp. *carnaticus*, and *S. sciuri* subsp. *rodentium*.
• The taxonomic validity of these subspecies delineations requires further investigation using polyphasic approaches.

Purpose of the Study:

• To clarify the taxonomic legitimacy of the subspecies within *Staphylococcus sciuri*.
• To evaluate the distinctiveness of *S. sciuri* subsp. *sciuri*, *S. sciuri* subsp. *carnaticus*, and *S. sciuri* subsp. *rodentium* using multiple characterization methods.

Main Methods:

• Polyphasic taxonomic analysis of 81 *S. sciuri* isolates and 10 reference strains.
• Characterization included extensive biotyping, MALDI-TOF mass spectrometry, automated ribotyping, 16S-23S rRNA gene intergenic transcribed spacer PCR fingerprinting, and repetitive sequence-based PCR fingerprinting.
• Sequencing of the RNA polymerase β-subunit gene (rpoB) was performed on selected strains.

Main Results:

• Individual techniques revealed high genetic heterogeneity among the analyzed *S. sciuri* strains.
• Despite the heterogeneity, clear differentiation into groups corresponding to the proposed subspecies was not consistently observed across the applied methods.

Conclusions:

• The study proposes rejecting the separation of *S. sciuri* into its current subspecies.
• Reclassification of *S. sciuri* subsp. *sciuri*, *S. sciuri* subsp. *carnaticus*, and *S. sciuri* subsp. *rodentium* as a single species, *S. sciuri*, is suggested.