Acute dehiscence of a valve prosthesis 5 years after implantation

Area of Science:

• Infectious Diseases
• Cardiology
• Microbiology

Background:

• Propionibacterium acnes is a common skin commensal, infrequently implicated in serious infections like endocarditis.
• Infectious endocarditis on prosthetic valves, especially mechanical ones, requires prompt diagnosis and treatment.
• Valvular dehiscence can occur post-surgery, sometimes without overt signs of infection.

Observation:

• A 48-year-old male with a history of mitral valve replacement presented with acute heart failure symptoms.
• Transesophageal echocardiography revealed dehiscence of the mechanical mitral prosthesis, necessitating urgent reoperation.
• Initial blood cultures were negative, but tissue cultures, after extended incubation, grew Propionibacterium acnes.

Findings:

• The patient's prosthetic valve endocarditis was attributed to Propionibacterium acnes, a rare pathogen in this context.
• Diagnosis was challenging due to initially negative blood cultures and the need for prolonged incubation of tissue samples.
• The case highlights the potential for P. acnes to cause endocarditis on prosthetic material.

Implications:

• Clinicians and laboratories must maintain close communication regarding sample handling and incubation times for suspected endocarditis.
• Extended incubation periods for blood and tissue cultures are vital for detecting fastidious or slow-growing organisms like P. acnes.
• This case underscores the importance of considering unusual pathogens in prosthetic valve endocarditis, even in the absence of typical infectious signs.