Actinomyces europaeus Brain Abscess of Otogenic Origin: A Rare Case and Literature Review

Actinomyces europaeus is an anaerobic, Gram-positive, branching filamentous bacterium that rarely causes human infection and is typically associated with skin and soft tissue infections. Central nervous system (CNS) involvement is extremely rare. This report presents the first CNS-localized A. europaeus case from Türkiye. A 45-year-old male presented with severe headache and weakness in the left upper extremity, and imaging revealed a right temporal lobe abscess. Actinomyces europaeus was isolated from the abscess following surgical drainage. The patient received intravenous ampicillin for 6 weeks, followed by oral amoxicillin, completing a six-month course of therapy. Complete clinical recovery was achieved with combined surgical management and prolonged antibiotic therapy. This case highlights the importance of considering rare pathogens in the differential diagnosis of patients with chronic otologic infections.