Pulmonary nocardiosis caused by in patients with complex lung disease: Two case reports

Kazuma Yagi, Makoto Ishii, Ho Namkoong, Takahiro Asami, Hiroshi Fujiwara, Tomoyasu Nishimura, Fumitake Saito, Yoshifumi Kimizuka, Takanori Asakura, Shoji Suzuki, Tetsuro Kamo, Sadatomo Tasaka, Tohru Gonoi, Katsuhiko Kamei, Tomoko Betsuyaku, Naoki Hasegawa

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

Pulmonary nocardiosis frequently occurs in immunocompromised hosts and in some immunocompetent hosts with chronic lung disease; however, few reports have described pulmonary nocardiosis with nontuberculous mycobacterial lung infection. Here we report for the first time two cases of pulmonary nocardiosis caused by Nocardia cyriacigeorgica associated with Mycobacterium avium complex (MAC) lung disease caused by M. avium. Case presentation: Case 1 is that of a 72-year-old Japanese man with untreated MAC lung disease, who was diagnosed with rheumatoid arthritis and initiated on methotrexate. After 3 years of methotrexate therapy, the patient remained smear-negative and culture-positive for MAC, but also became smear-positive for Nocardia species. He received trimethoprim/sulfamethoxazole, and his symptoms and lung infiltrates improved. Case 2 is that of an immunocompetent 53-year-old Japanese woman with MAC lung disease, who was treated with a combined therapy of clarithromycin, rifampicin, ethambutol, and levofloxacin. MAC sputum culture was negative after 1 year of combined treatment, which was maintained for 2 years. After four treatment-free years, Nocardia species were occasionally isolated from her sputum, although MAC was rarely isolated from sputum cultures over the same period. In both cases, the Nocardia species were identified as the recently defined N. cyriacigeorgica by 16S ribosomal RNA gene sequencing. Conclusion: We report two cases of pulmonary nocardiosis caused by N. cyriacigeorgica associated with MAC lung disease caused by M. avium and suggest that N. cyriacigeorgica may be a major infective agent associated with MAC lung disease.

Original languageEnglish
Article number684
JournalBMC infectious diseases
Volume14
Issue number1
DOIs
Publication statusPublished - 2014 Aug 12

Keywords

  • Mycobacterium avium complex lung disease
  • Nocardia cyriacigeorgica
  • Pulmonary nocardiosis

ASJC Scopus subject areas

  • Infectious Diseases

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