Intractable Nocardial mycetoma with possible colonisation by Candida species

Area of Science:

• Medical Mycology
• Infectious Diseases
• Dermatology

Background:

• Mycetoma is a chronic, granulomatous infectious disease affecting subcutaneous tissue, typically caused by fungi or aerobic actinomycetes.
• Nocardia species are known causative agents of mycetoma, often presenting as localized infections.

Observation:

• A Japanese male in his 30s presented with a 7-year history of painless nodules and ulcers on his right leg following a dog bite in Bali, Indonesia.
• Tissue cultures revealed Nocardia vulneris as the primary pathogen, with concurrent isolation of Candida parapsilosis and Candida tropicalis.

Findings:

• The patient was diagnosed with mycetoma attributed to Nocardia vulneris, potentially complicated by co-infection with Candida species.
• Initial treatment with minocycline hydrochloride and sulfamethoxazole trimethoprim showed limited efficacy.
• Addition of posaconazole resulted in significant clinical improvement, suggesting synergistic or additive effects.

Implications:

• This case highlights the potential for Nocardia vulneris to cause mycetoma in immunocompetent individuals.
• Co-colonization with less virulent yeasts may complicate treatment, necessitating a comprehensive therapeutic strategy.
• Combination therapy including antifungals like posaconazole may be crucial for managing recalcitrant mycetoma cases.