Hematogenous vertebral osteomyelitis caused by vaginal microbiota: metagenomic resolution of a polymicrobial anaerobic case.

We describe a rare case of a 35-year-old female patient suffering from polymicrobial hematogenous vertebral osteomyelitis caused by vaginal microbiota following sexual intercourse. Anaerobic blood cultures yielded Fannyhessea vaginae and Gemelliphila asaccharolytica, and intraoperative tissue cultures from decompression surgery identified Gardnerella vaginalis. Beyond Fannyhessea vaginae and Gemelliphila asaccharolytica, 16S rRNA gene Nanopore sequencing of surgical tissue also detected high amounts of Parvimonas parva, Peptostreptococcus anaerobius, Marseillibacter massiliensis, and Gemelliphila palaticanis. Antibiotic treatment with broad anaerobic coverage resulted in complete clinical resolution. Retrospective metagenomic analysis of a cervical swab obtained 9 months earlier revealed Fannyhessea vaginae and G. vaginalis to be already present in the vaginal microbiota. This case highlights the potential for hematogenous dissemination of vaginal anaerobes after sexual intercourse and underscores the diagnostic challenges posed by fastidious anaerobic bacteria. Molecular techniques are helpful tools in uncovering pathogens that may escape conventional culture methods.