Dolosicoccus paucivorans gen. nov., sp. nov., isolated from human blood

This paper describes the isolation and characterization of a novel bacterium from a blood culture of a 78-year-old male nursing home resident with pneumonia. The organism, strain CCUG 39307T, is a Gram-positive, catalase-negative, chain-forming coccus that was biochemically and phylogenetically distinct from previously known species. Using 16S rRNA gene sequencing, phenotypic tests, and whole-cell protein analysis, researchers determined the bacterium represents a new phylogenetic lineage closely related to, but distinct from, the genera Facklamia and Globicatella. The organism was notably biochemically unreactive, utilizing few carbohydrates and showing limited enzymatic activity. Based on these findings, the authors propose classification of this bacterium as a new genus and species: Dolosicoccus paucivorans, with the species name reflecting its limited carbohydrate utilization. The strain remained unidentifiable by standard clinical laboratory methods before this characterization. The patient recovered following antibiotic treatment with cefuroxime and ceftazidime.

Key findings

• A novel Gram-positive, catalase-negative coccus isolated from human blood was classified as a new genus and species, Dolosicoccus paucivorans, based on 16S rRNA gene sequencing and phenotypic analysis.
• The organism is phylogenetically distinct from Facklamia and Globicatella species, forming a separate lineage with >8% sequence divergence from related taxa.
• Dolosicoccus paucivorans is biochemically unreactive with minimal carbohydrate fermentation ability, distinguishing it from other catalase-negative Gram-positive cocci through specific enzyme production patterns and substrate utilization profiles.
• The bacterium possesses a DNA G+C content of 40.5 mol% and is vancomycin-sensitive, consistent with the low G+C lactic acid bacteria group.