Primary Brain Abscess Caused by Nocardia terpenica: a Case Report and Literature Review.

BACKGROUND

Nocardia terpenica is an exceptionally rare opportunistic pathogen, with infections scarcely documented in clinical practice. We report the first case of primary brain abscess caused by Nocardia terpenica and present a comprehensive review of the microbiological features and clinical presentations associated with this pathogen.

METHODS

The patient underwent intracranial puncture and drainage due to a brain abscess. During the procedure, cerebrospinal fluid (CSF) was collected for culture. The isolated pathogen was subjected to Gram staining and modified acid-fast staining. Identification was carried out using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Susceptibility testing was performed using the microbroth dilution method.

RESULTS

CSF culture on blood agar plates yielded small, white, agar-biting colonies. Gram staining revealed Gram-positive branching bacilli, and modified acid-fast staining was positive, suggesting Nocardia spp. MALDI-TOF MS (AnTu, China) confirmed Nocardia terpenica. Microbroth dilution susceptibility testing (35°C, 5 days) showed the isolate was susceptible to trimethoprim-sulfamethoxazole, minocycline, ciprofloxacin, moxifloxacin, clarithromycin, linezolid, tobramycin, amikacin, and imipenem, but resistant to ceftriaxone and amoxicillin-clavulanate. The patient was treated with linezolid, meropenem, and trimethoprim-sulfamethoxazole.

CONCLUSIONS

For patients with Nocardia terpenica infections, it is essential to identify the pathogen as early as possible and to provide adequate treatment for a sufficient duration.