[Infective endocarditis by Rhizobium radiobacter. A case report]

Area of Science:

• Microbiology
• Infectious Diseases
• Cardiology

Background:

• Rhizobium radiobacter is a Gram-negative bacterium, typically found in soil and rarely pathogenic to humans.
• It has been linked to bacteremia in immunocompromised individuals, often due to intravascular catheter colonization.

Observation:

• A 47-year-old male with chronic kidney disease on hemodialysis presented with prolonged fever.
• Echocardiography revealed tricuspid valve vegetation and significant regurgitation.
• Blood cultures identified Rhizobium radiobacter, resistant to ceftriaxone but sensitive to imipenem, amikacin, and ampicillin.

Findings:

• The patient received empirical antibiotics (cefotaxime and vancomycin), followed by targeted therapy with vancomycin and imipenem.
• Clinical and paraclinical improvement was observed within seven days.
• Resolution of tricuspid valve vegetation was confirmed by echocardiography upon discharge.

Implications:

• This case demonstrates that Rhizobium radiobacter can cause infective endocarditis, particularly in patients with intravascular catheters.
• Prompt identification and appropriate antibiotic selection are crucial for managing R. radiobacter endocarditis.
• Highlights the need for vigilance regarding unusual pathogens in immunocompromised patients with indwelling devices.