Early diagnosis of streptococcus cristatus in blood culture-negative infective endocarditis by capture-based metagenomic next-generation sequencing: a case report.

Background: Infective endocarditis (IE) is a life-threatening infectious cardiac condition characterized by therapeutic complexity and high mortality rates, for which precise pathogen identification is critical to guide accurate treatment. Although this disease is frequently caused by commensal microorganisms of the oral flora, including Case presentation: A 59-year-old male patient was admitted to our intensive care unit due to chest tightness and shortness of breath persisting for 10 days, with symptoms worsening over the last 6 h, including dyspnea and an inability to lie down. After the patient was admitted to the hospital for comprehensive examinations, a preliminary clinical diagnosis of IE, aortic valve vegetation formation, acute non-ST-segment elevation myocardial infarction, and heart failure was established. The patient had negative preoperative blood culture results and received empiric therapy with moxifloxacin combined with piperacillin-tazobactam for infection control, subsequently undergoing cardiac surgery. Intraoperatively obtained valve vegetations were sent for pathological testing, tissue bacterial culture, and capture-based mNGS (metagenomic next-generation sequencing) testing. The capture-based mNGS results for the vegetation was returned as Conclusions: This case highlights a rare instance of