A case report of brain abscess caused by Nocardia cyriacigeorgica in a diabetic patient

INTRODUCTION: Nocardia are Gram-positive partially acid-fast bacilli capable of inducing a wide range of infections in patients with immunodeficiency, AIDS, cancer, lupus erythematous and diabetes. Nocardia cyriacigeorgica was first isolated in 2001 from a patient with chronic bronchitis. Since then, there have been reports on the clinical significance of this organism in patients with bronchitis, brain abscess and lung diseases. We, herein, report a case of brain abscess in an elderly diabetic patient from Iran. CASE PRESENTATION: The patient was a 73 year-old woman admitted to hospital due to severe headache and shortness of breath. The patient had lived with diabetes for 20 years and suffered from chronic foot ulcer. She was admitted to hospital with fever, weakness, drowsiness and vomiting. Clinical examination and the head CT scan of the left frontal lobe of the brain revealed a metastatic carcinoma involving skull bone in the tumor that resulted in two surgical operations in the following two years. The brain abscess biopsy revealed an infection with Nocardia cyriacigeorgica confirmed by phenotypic and molecular tests including a PCR-based amplification of a target genetic marker, a 596 bp fragment of 16S rRNA gene, followed by almost full 16S rRNA sequencing. CONCLUSION: The rare infections, such as brain abscess with Nocardia, are easily neglected or misdiagnosed due to the fastidious nature of the organism and inadequate microbiological experience of laboratories in the hospitals of developing countries. This case shows that hospitals should consider a better laboratory protocol to deal with the clinical cases in which fastidious organisms, and in particular Nocardia, are involved.