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Proteus mirabilis - a rare cause of non-HACEK Gram-negative infective endocarditis
A De Wilton1, M Margaritis1, H Mills1
1Hospital for Tropical diseases, University College London Hospital, London, UK.
Abstract:
Infective endocarditis caused by Proteus mirabilis is strikingly rare. Here, we describe the case of an 86-year old man with five recurrent septic episodes over a period of three months associated with Proteus mirabilis bacteraemia secondary to underlying Proteus endocarditis. The final diagnosis was made based on clinical findings, blood culture results and transoesophageal echocardiogram. The patient was treated medically with 6 weeks of ceftriaxone and long-term oral ciprofloxacin. On completion of intravenous therapy the patient remained well. We performed a literature review and found this to be only the fourth confirmed case of Proteus mirabilis endocarditis successfully treated with antibiotic therapy alone. This case highlights an important but rare cause of endocarditis, reinforcing the need to consider this diagnosis in recurrent Gram-negative bacteraemia even if by an atypical organism.
Insights
Infective endocarditis caused by Proteus mirabilis is rare. This case report details successful antibiotic treatment for recurrent Proteus mirabilis bacteremia, highlighting a rare cause of endocarditis.
Area of Science:
- Infectious Diseases
- Cardiology
- Microbiology
Background:
- Infective endocarditis is a serious infection of the heart valves.
- Proteus mirabilis is an uncommon cause of endocarditis, typically associated with urinary tract infections.
Observation:
- An 86-year-old male presented with five recurrent septic episodes over three months.
- Bacteremia was consistently linked to Proteus mirabilis, originating from underlying Proteus endocarditis.
Findings:
- Diagnosis was confirmed via clinical presentation, blood cultures, and transesophageal echocardiogram.
- The patient received a 6-week course of ceftriaxone and long-term oral ciprofloxacin.
- This represents the fourth reported case of Proteus mirabilis endocarditis successfully treated with antibiotics alone.
Implications:
- This case underscores the importance of considering Proteus mirabilis in recurrent Gram-negative bacteremia.
- Highlights the potential for successful medical management of rare infective endocarditis cases.
- Emphasizes the need for thorough investigation in patients with persistent, unexplained Gram-negative infections.
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