Disseminated Nocardiosis in an Immunocompetent Individual Infected with <i>Nocardia brasiliensis</i>, an Opportunistic Agent

Abstract

Introduction: Nocardia species are described as opportunistic pathogens that mainly cause pulmonary nocardiosis in immunocompromised individuals, particularly in patients with acquired immune deficiency syndrome (AIDS), intravenous drug abusers, strongly burned victims, the Cushing syndrome, the ones underlying transplantation, and prolonged use of corticosteroids. Case Presentation: The current paper reported a case of disseminated nocardiosis in a 28-year-old Iranian male who had type 2 diabetes mellitus with prolonged use of corticosteroid for the last 5 years. He was admitted to the department of infectious diseases at Shahid Beheshti hospital, Tehran, Iran, following a complaint of pneumonia (chest pain) and presented a subcutaneous purple nodule on the left thigh without pain. Direct microscopic examination revealed numerous filamentous branching and rod-shaped bacilli. The tentative diagnosis of chronic inflammation with nocardiosis was made. In addition, tiny, chalky white and irregular colonies emitting an earthy odor appeared on blood and chocolate agar and were identified as Nocardia brasiliensis by sequencing of 16S rRNA gene as a valuable method to identify clinical isolates. Combination therapy was performed by entire surgical excisions and intravenous TMP-SMX (160/800 mg/bid; IV) and meropenem 1g/tid. The patient’s condition improved after 8 days and he was discharged. Conclusions: Combination therapy with surgical excision has a synergistic effect and appears to be the best treatment for extended lesions. However, new potent antibacterial drugs may help to improve the management of such infections when there are sufficient data on their in vitro activity.