Mycoplasma hominis central nervous system infection diagnosed by metagenomic next- generation sequencing: A case report

Abstract

Mycoplasma hominis (M. hominis) is a rare cause of intracranial infection with diagnostic challenges due to its fastidious nature, nonspecific symptoms mimicking common nervous system infection (e.g., viral encephalitis), and absence of characteristic neuroimaging. Traditional methods (culture/ serology) often yield false negatives, delaying appropriate therapy. Metagenomic Next-Generation Sequencing (mNGS) provides an unbiased solution for such pathogens. We report a 50-year-old male presented with recurrent fever and coma after hematoma evacuation and external ventricular drainage for cerebral hemorrhage. Empirical antimicrobial therapy (ceftriaxone → piperacillin-tazobactam → vancomycin) was ineffective. Cerebrospinal fluid (CSF) analysis confirmed intracranial infection, leading to escalation to meropenem plus intravenous/intrathecal vancomycin, yet clinical and CSF parameters showed no improvement. Although traditional culture of pathogens and serological testing yielded negative results, M. hominis was detected in CSF by mNGS mNGS on postoperative day 19. Targeted therapy with moxifloxacin and doxycycline resulted in marked clinical improvement: fever resolved and CSF abnormalities normalized.

Conclusion: This case highlights mNGS as pivotal for diagnosing fastidious pathogens like M. hominis in culture-negative intracranial infections, enabling a critical shift from failed empirical therapy to successful pathogen-directed treatment. It further underscores the indispensable role of the clinical pharmacist in optimizing antimicrobial selection and monitoring based on mNGS findings. When empirical therapy fails and pathogen identification remains elusive in CNS infections, mNGS emerges as a valuable diagnostic option to guide targeted treatment.