Escherichia coli prosthetic valve endocarditis from a non-genitourinary source

Area of Science:

• Infectious Diseases
• Cardiology
• Microbiology

Background:

• Escherichia coli (E. coli) is an uncommon cause of infective endocarditis, typically lacking virulence factors for heart valve adherence.
• Risk factors for E. coli endocarditis include advanced age, female sex, diabetes, immunosuppression, and cardiac devices, with genitourinary infections being a common source.

Observation:

• A case of a 55-year-old male with a prosthetic mitral valve presented with symptoms of endocarditis.
• Diagnosis was confirmed by positive blood cultures for E. coli and a transesophageal echocardiogram showing a vegetation on the prosthetic valve.
• An indolent gastrointestinal source was suspected, with imaging showing mild periappendiceal stranding.

Findings:

• The patient received a 6-week course of ceftriaxone and gentamicin, followed by suppressive trimethoprim-sulfamethoxazole.
• Review of ten recent cases of prosthetic valve endocarditis due to E. coli revealed common features.
• Non-genitourinary bacteremia sources, increased surgical interventions, and a decreasing mortality rate were noted.

Implications:

• This case and literature review highlight evolving trends in E. coli prosthetic valve endocarditis.
• Understanding non-genitourinary sources and the role of surgery is crucial for effective management.
• The declining mortality rate suggests improved treatment strategies and outcomes for this rare condition.