Infective Endocarditis Caused by Streptococcus Sinensis in a Patient with Bioprosthetic Aortic Valve: A Case Report and Literature Review

Background: Infective endocarditis caused by Streptococcus sinensis is exceedingly rare, with only limited cases reported. Here, we present the first documented case of prosthetic valve endocarditis attributed to Streptococcus sinensis. . Case Presentation: A 40-year-old Chinese female was admitted with a 45-day history of intermittent fever. The presumed diagnosis was a pulmonary infection and antibiotic therapies failed to alleviate her symptoms. On admission, infective endocarditis was suspected, considering the history of aortic valve replacement and recent dental procedure without prophylactic antibiotics. Transesophageal echocardiography disclosed a 3-millimeter vegetation in the prosthetic aortic valve, and metagenomic next-generation sequencing and mass spectrometry identified Streptococcus sinensis. . The patient was diagnosed with infective endocarditis. Antibiotic treatments resulted in temporary clinical improvements, although fluctuations in temperature and inflammatory markers led to multiple attempts at antibiotic therapies. At last, the patient underwent an elective aortic valve replacement with a favorable prognosis. Conclusion: In this case, we demonstrated prosthetic valve endocarditis caused by Streptococcus sinensis, , which is an extremely rare pathogen. All reported endocarditis cases caused by Streptococcus sinensis were reviewed and summarized. Most of these patients had rheumatic heart diseases or congenital heart diseases. Antibiotic prophylaxis is important for high-risk procedures. Timely identification of the bacterium is crucial for diagnosis and treatment. Overall, infective endocarditis caused by this bacterium had a good prognosis.