Infective endocarditis due to Propionibacterium species

Area of Science:

• Infectious Diseases
• Cardiology
• Microbiology

Background:

• Propionibacterium species are infrequently recognized as causative agents of infective endocarditis.
• These bacteria are often misidentified as skin flora contaminants in blood cultures, delaying diagnosis.
• Characterizing the clinical presentation and management of Propionibacterium endocarditis is essential for improving patient outcomes.

Observation:

• A retrospective review of Mayo Clinic cases and a literature search identified 70 patients with Propionibacterium endocarditis.
• The majority of infections (79%) involved prosthetic material, including prosthetic valves and cardiac devices.
• Abscess formation complicated 36% of cases, and 81% of patients required surgery.

Findings:

• Infective endocarditis caused by Propionibacterium species predominantly affects middle-aged males and is strongly associated with cardiovascular devices.
• Blood cultures were positive in 62% of cases, with microbiological confirmation achieved through valve tissue cultures or molecular methods in cases with negative blood cultures.
• Crude in-hospital mortality was 16%, with treatment typically involving penicillin derivatives and surgical intervention.

Implications:

• Infective endocarditis should be strongly suspected in patients with cardiovascular devices when Propionibacterium species are isolated from multiple blood cultures.
• Early recognition and appropriate management, including surgical debridement and device removal when necessary, are critical.
• Further research into optimal antibiotic regimens and long-term outcomes for Propionibacterium endocarditis is warranted.