Beyond the Usual Pathogens: Community-Acquired Meningoencephalitis Caused by Streptococcus equi in an Immunocompetent Adult.

Streptococcus equi is a rare zoonotic pathogen that only occasionally causes invasive central nervous system infections in humans. We report the case of a previously healthy 50-year-old man who presented with fever and altered mental status in the setting of recent animal exposure. Cerebrospinal fluid analysis was consistent with acute bacterial meningitis, while direct microscopy and multiplex polymerase chain reaction identified S. equi. Antimicrobial susceptibility testing confirmed susceptibility to ceftriaxone. Despite early initiation of intravenous ceftriaxone and adjunctive dexamethasone, the patient's course was complicated by generalized status epilepticus requiring intensive care support. He subsequently showed progressive neurological recovery with a favorable outcome. This case underscores the importance of considering S. equi as a potential cause of community-acquired bacterial meningoencephalitis in patients with relevant zoonotic exposure and highlights the value of rapid molecular diagnostics for early pathogen identification and targeted antimicrobial therapy.