Nocardia asteroides
Nocardia brain abscesses typically occur in immunocompromised patients. Most cases of nocardiosis are caused by the Nocardia asteroides complex and Nocardia brasiliensis.
Nocardia farcinica is a species of bacteria and a member of the genus Nocardia. This species is very similar in phenotype to Nocardia asteroides, to the degree that some isolates of N. asteroides were later found to be Nocardia farcinica.
Nocardia brain abscesses typically occur in immunocompromised patients. Most cases of nocardiosis are caused by the Nocardia asteroides complex and Nocardia brasiliensis. Here, we present a patient with a Nocardia abscessus brain abscess.
The diagnosis was confirmed by DNA sequencing, and the organism was susceptible to linezolid, clarithromycin, ceftriaxone, imipenem, tobramycin, amikacin, minocycline and sulfamethoxazole. The patient was successfully treated medically in combination with surgical excision 1).
A case of 73 years old man who is a known case of rheumatoid arthritis for more than 15 years and was on Methotrexate and Prednisolone. Now presented with generalized tonic clonic seizures. His Magnetic Resonace Imaging (MRI) scan showed a ring enhancing lesion with mild surrounding oedema in right posterior parietal cortex. Based on the finding, the most probable diagnosis of cerebral abscess was suggested. Patient underwent right sided craniotomy with aspiration of abscess. Serum Gram staining showed branching Gram-positive rods, and serum culture showed colonies of Nocardia Asteroides. He was started on Sulfamethoxazole-Trimethoprim. On follow-up examination, the patient showed marked improvement clinically and was discharged in stable condition on long term antibiotic therapy. This case highlights the importance of including nocardia on the differential diagnosis especially in patients who present with abnormal MRI scan findings that mimic tuberculoma or neoplastic disease. Clinical awareness of this condition could expedite the diagnostic process and help improve morbidity and mortality 2).