Streptococcus gallolyticus endocarditis on a prosthetic tricuspid valve: a case report and review of the literature

BACKGROUND: Streptococcus gallolyticus subspecies gallolyticus is a known pathogen that causes infective endocarditis, and most cases involve the left heart valves. We present the first reported case of prosthetic tricuspid valve endocarditis caused by this microorganism. Relevant literature is reviewed. CASE PRESENTATION: A 67-year-old Jewish female with a history of a prosthetic tricuspid valve replacement was admitted to the emergency department because of nonspecific complaints including effort dyspnea, fatigue, and a single episode of transient visual loss and fever. No significant physical findings were observed. Laboratory examinations revealed microangiopathic hemolytic anemia and a few nonspecific abnormalities. Transesophageal echocardiogram demonstrated a vegetation attached to the prosthetic tricuspid valve. The involved tricuspid valve was replaced by a new tissue valve, and Streptococcus gallolyticus subspecies gallolyticus was grown from its culture. Prolonged antibiotic treatment was initiated. CONCLUSIONS: Based on this report and the reviewed literature, Streptococcus gallolyticus should be considered as a rare but potential causative microorganism in prosthetic right-sided valves endocarditis. The patient’s atypical presentation emphasizes the need for a high index of suspicion for the diagnosis of infective endocarditis.