<i>Nocardia cyriacigeorgica</i> : An unusual etiological agent of brain abscess in a patient with myeloma

Nocardiosis is an opportunistic infection caused by weakly Gram-positive, partially acid-fast, filamentous bacteria of the genus Nocardia . Nocardiosis of the central nervous system (CNS) may manifest as single/multiple abscesses. It could be misinterpreted as a tumor or space-occupying lesion caused by other infectious agents on imaging. Here, we present a case of nocardial brain abscess in a patient with myeloma. Brain biopsy was performed from the intracranial lesion; modified Ziehl-Neelsen staining of the aspirated biopsy material revealed filamentous, acid-fast, branching bacteria, suggestive of Nocardia species. Growth was obtained on blood agar and Lowenstein-Jensen media after 72 hours of incubation. The growth was confirmed by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) (BioMérieux France) as Nocardia cyriacigeorgica . The patient was administered intravenous imipenem and trimethoprim-sulfamethoxazole, resulting in significant clinical improvement. Thorough maintenance, interspersed, consolidated therapy with imipenem for 10 days every month was continued for 9 months to prevent relapse.