Metagenomic next-generation sequencing identified a brain abscess caused by mixed oral anaerobe infection: A case report

Abstract

Fusobacterium vincentii brain abscesses are relatively rare. Here, we report our treatment of an anaerobic brain abscess caused by a mixed infection of Parvimonas micra, Streptococcus constellatus, Fusobacterium vincentii, and Bacteroides heparinolyticus diagnosed by metagenomic next-generation sequencing (mNGS). This is the first reported case of Fusobacterium vincentii in a brain abscess. This case highlights the possibility that oral anaerobic microbes can cause a brain abscess and demonstrates that mNGS has the potential to be deployed to provide rapid infection diagnosis and rationalize antimicrobial therapy for brain abscesses.

Keywords: Anaerobic brain abscess; Bacteroides heparinolyticus; Fusobacterium vincentii; Parvimonas micra; Streptococcus constellatus; mNGS.

Graphical abstract

Fig. 1

(A) Axial T2-weighted fluid-attenuated image revealing a hyperintense lesion surrounded by a thin hypointense ring of about 2.9 cm × 2.7 cm × 3.3 cm in the frontal-parietal region. (B) Shallower cerebral sulci and fissures.

Fig. 2

Results of bacterial culture under an optical microscope.

Fig. 3

Phylogenetic tree of single-copy lineal homologous genes recovered from a pus sample in a hospital in China. (A) Phylogenetic tree of 38 Streptococcus anginosus group strains (1 sequenced strain and 37 NCBI database strains). (B) Phylogenetic tree of 32 Fusobacterium nucleatum strains (1 sequenced strain and 31 NCBI database strains). (C) Phylogenetic tree of 11 Parvimonas micra strains (1 sequenced strain and 10 NCBI database strains).

Fig. 4

Average nucleotide identity (ANI) analysis of sequenced and NCBI database strains. (A) ANI analysis of 1 sequenced Fusobacterium vincentii strain and 31 NCBI database strains. (B) ANI analysis of 11 Parvimonas micra strains. (C) ANI analysis of 38 Streptococcus anginosus group strains (1 sequenced strain and 37 NCBI database strains).