We herein describe the case of a 40-year-old woman in the Central-West region of Brazil with a nine-year history of HIV infection, who was receiving stavudine, lamivudine, and efavirenz. She had a CD4 T lymphocyte count of 42/mm3, CD8 T lymphocyte count of 642/mm3, and her most recent viral load was 6,275 copies/mL. She presented with mediastinal and cerebral manifestations, characterized by a left hemithoracic tumor, left pleural effusion, evolving hypoesthesia in the phalanges of the right hand, headache, presence of a left thoracic collection, and a hypodense left parieto-temporal lesion on computed tomography, caused by Nocardia asiatica. The patient recovered after treatment with sulfamethoxazole/trimethoprim, ceftriaxone, and amikacin; thoracotomy; and drainage of the extensive thoracic collection. Nocardiosis is an uncommon infection that occurs in immunocompromised individuals, such as HIV-positive patients, patients with oncological diseases, or those receiving immunosuppressive drugs1,2.
Analysis of pleural and cerebral secretions detected Nocardia spp., a Gram-positive (Figure A), filamentous, strictly aerobic, partially alcohol- and acid-resistant bacterium (Figure B). The laboratory identification of Nocardia spp. is difficult as it is often confused with mycobacteria2. N. asiatica was also identified by direct microscopic examination with 20% potassium hydroxide (Figure C). Sequencing of the 1376 bp 16S rRNA from this isolate (GenBank accession no. KF562729) revealed 100% identity with that of the N. asiatica strain DSM 44668 (GenBank accession no. GQ217495). Furthermore, phylogenetic analysis showed the formation of a clade with N. asiatica, emphasizing the importance of genotypic analysis for the diagnosis of nocardiosis3.
