Disseminated Petriellidium boydii and pacemaker endocarditis

Area of Science:

• Mycology
• Infectious Diseases
• Cardiology

Background:

• Mixed connective tissue disease (MCTD) can compromise the immune system.
• Corticosteroid therapy for autoimmune conditions increases susceptibility to opportunistic infections.
• Petriellidium boydii (P. boydii) is a fungus ubiquitous in soil, increasingly recognized as an opportunistic pathogen.

Observation:

• A 62-year-old female gardener with MCTD on corticosteroid therapy developed disseminated P. boydii infection.
• The infection manifested as fatal right-sided endocarditis with massive vegetations on the tricuspid valve.
• A pacemaker catheter inserted eight years prior was encased by the fungal vegetations.

Findings:

• P. boydii was isolated from 11 consecutive blood cultures, a novel finding for this organism.
• This case represents the first reported instance of endocarditis caused by P. boydii.
• Morphologic findings revealed extensive fungal growth obliterating the tricuspid valve orifice.

Implications:

• Highlights the potential for P. boydii to cause severe, invasive infections in immunocompromised individuals.
• Underscores the importance of considering fungal endocarditis in patients with risk factors like immunosuppression and indwelling devices.
• Suggests environmental exposure, such as gardening, as a potential route of infection for P. boydii.