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For further information, see CMDT Part 33-34: Nocardiosis
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Nocardia species are an aerobic filamentous soil bacterium that can cause pulmonary and systemic nocardiosis
Commonly identified nocardia species include members of the Nocardia asteroides complex and Nocardia brasiliensis
Bronchopulmonary abnormalities (eg, alveolar proteinosis) predispose to colonization, but infection is unusual unless the patient is also receiving systemic corticosteroids or is otherwise immunosuppressed
Central nervous system (CNS) involvement commonly accompanies pulmonary infection
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Pulmonary involvement usually begins with malaise, loss of weight, fever, and night sweats
Cough and production of purulent sputum are the chief complaints
Dissemination may involve any organ
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N asteroides is a branching, filamentous gram-positive bacterium that is weakly acid-fast
Identification is made by culture
Chest radiograph
Brain imaging should be considered even in absence of clinical symptoms and signs of CNS infection to rule out occult abscess
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Trimethoprim-sulfamethoxazole (TMP-SMZ)
For isolated cutaneous infections
For disseminated or pulmonary infections: 15 mg/kg/day (based on TMP)
Resistance to TMP-SMZ is increasing and initiating treatment with two drugs should be considered while awaiting antibiotic susceptibilities in cases of disseminated or severe localized disease
Alternative agents or drugs that can be given in combination with TMP-SMZ
Imipenem, 500 mg intravenously every 6 hours
Amikacin, 7.5 mg/kg intravenously every 12 hours
Minocycline, 100–200 mg orally or intravenously twice daily
Surgical procedures such as drainage and resection may be needed as adjunctive therapy
Response may be slow, and therapy should be continued for at least 6 mo
The prognosis in systemic nocardiosis is poor when therapy is delayed