Emerging role of Actinomyces meyeri in brain abscesses: A case report and literature review

We describe a case of a 29-year-old man from Pakistan who presented with progressive neurologic symptoms over 1 week and was found to have a right parietal cerebral abscess. Neurosurgical drainage cultures showed growth of Actinomyces meyeri, Streptococcus intermedius, and Parvimonas micra. An abscessed molar was identified as the likely port of entry and was extracted. The patient was treated with metronidazole, vancomycin, and doxycycline because of prior anaphylaxis to penicillin. At 6-month follow-up, repeat magnetic resonance imaging showed no signs of residual abscess. Culture-independent identification techniques (e.g., ribosomal sequencing) increasingly identify Actinomyces meyeri as a causative agent and significant pathogen in spontaneous brain abscesses. As understanding about Actinomyces meyeri's prevalence and pathogenesis improves, questions arise about optimal treatment strategy, which we discuss based on a literature review.