Mixed Candida and Brucella Aortic Valve Endocarditis With Aortic Root Abscess Requiring a Bentall Procedure: A Case...

Mixed-pathogen infective endocarditis is uncommon and may be difficult to recognize when the clinical course is prolonged and nonspecific. We report a case of mixed Candida albicans and Brucella melitensis native aortic valve endocarditis in a 37-year-old previously healthy man who presented with five months of intermittent fever, chills, anorexia, fatigue, 7 kg weight loss, progressive dyspnea, and intermittent chest pain. Physical examination revealed fever, sinus tachycardia, wide pulse pressure, elevated jugular venous pressure, bibasilar crackles, and a loud early diastolic murmur. Laboratory testing was notable for leukocytosis, anemia, mild thrombocytosis, and elevated inflammatory markers. A transthoracic echocardiogram demonstrated severe aortic regurgitation with a large 19 mm aortic valve vegetation causing holodiastolic flow reversal in the descending thoracic aorta. A transesophageal echocardiogram revealed two large mobile vegetations causing severe leaflet malcoaptation with possible periannular extension. A cardiac CT scan revealed thickening of the aortic root consistent with abscess formation. Blood cultures were positive for Candida albicans and Brucella melitensis. Brucella serology was positive, with an agglutination titer of 1:640. The patient developed pulmonary edema requiring an urgent Bentall procedure with a mechanical composite graft. Valve tissue cultures were positive for Candida albicans, and histopathology from the resected valve was consistent with acute-phase infective endocarditis with features of necrosis, fibrin, and debris. The patient was placed on postoperative antifungal treatment with caspofungin followed by fluconazole suppression, and on Brucella-directed treatment with doxycycline, rifampin, and levofloxacin for a planned six-month course of therapy. A postoperative whole-body PET/CT scan using fluorine-18 fluorodeoxyglucose (18F-FDG) did not demonstrate any residual cardiac infection or extracardiac infectious foci. The patient was doing well clinically at the three-month follow-up, with no signs or symptoms of heart failure and no evidence of relapse or recurrence of fever. This is a rare case of destructive native aortic valve endocarditis with mixed fungal and zoonotic bacterial etiologies that required urgent surgical source control and prolonged combined antimicrobial therapy.