Brain abscess caused by Nocardia thailandica infection in systemic lupus erythematosus patient with steroid therapy

Abstract

Background: Nocardia is an aerobic Gram-negative bacillus belonging to actinomycetes and has been reported to be an infectious disease in healthy individuals. However, more than 60% have some underlying illnesses and are said to be opportunistic infections.

Case description: The case was a 69-year-old man who had been on long-term steroids for systemic lupus erythematosus. He developed with nausea and gait disturbance and was suspected of having a brain abscess by imaging. Abscess drainage detects actinomycetes that appear to belong to the genus Nocardia and brain abscess by Nocardia thailandica using matrix-assisted laser desorption/ionization time-of-flight mass analysis (MALDITOFMS) I was diagnosed. He died during the course of the treatment, and his organs did not detect his N. thailandica at necropsy, so he concluded that bacterial death from long-term administration of antibiotics was the cause of death.

Conclusion: N. thailandica is a very rare bacterium belonging to Nocardia asteroides and is said to easily form brain lesions. In immunocompromised patients, prophylaxis with antibiotics and detailed examination of lung lesions for surveillance were considered necessary. This paper is the first report of a brain abscess caused by N. thailandica, including a review of the literature.

Keywords: Brain abscess; Long-term steroid therapy; Nocardia; Nocardia thailandica; Systemic lupus erythematosus.

Figure 1:

(a) Preoperative the brain CT in the axial plane shows the low-density area in the right parietal lobe. (b) The enhanced T1-weighted MRI axial image revealed that polycystic ring-enhancing lesions with surrounding vasogenic edema in the right parietal lobe. (c) Gram stain for brain pus showing Gram-positive actinomyces with beaded staining pattern. (×1000). (d) Kinyoun smear stain showing a cluster of filamentous branching rods that are partially acid fast, which is characteristic for Nocardia (×1000).

Figure 2:

(a) MALDI-TOF mass spectra of the extract from a patient’s abscess (b): Nocardia thailandica (identification score: 1.731) The comparison between the raw MALDI-TOF mass spectra and the most possibility reference mass spectra. Yellowish-green, yellowish, and reddish spectra indicated as correct, possible, and difference to the reference mass spectra of the database, respectively.

Figure 3:

Postmortem specimens of the patient. (a) Gross brain section showing a collapsed abscess in the right parietal lobe (arrow). (b) H.E. stain revealed that no viable bacteria was in and around the cerebral abscess (×100). (c) Gross appearance of lung showing an abscess occupying the right inferior lobe (arrow). (d) Aspergillus (arrow) and Candida (arrow head) genus were seen in the lung abscess stained with H.E. (×100).