Streptococcus anginosus Infective Endocarditis Complicated by a Paravalvular Aortic Abscess in a Patient With a Bicuspid Aortic Valve

We present a case of infective endocarditis (IE) caused by Streptococcus anginosus in a 39-year-old man with a previously diagnosed bicuspid aortic valve (BAV).Although S. anginosus is part of the normal human microbiota, its involvement in IE is uncommon.The patient presented with a six-week history of nonspecific constitutional symptoms; imaging revealed renal and splenic infarcts, and transoesophageal echocardiography demonstrated aortic valve vegetations with a paravalvular abscess.Blood cultures and molecular testing identified S. anginosus as the causative organism.He underwent aortic valve replacement with a mechanical prosthesis and aortic root reduction plasty; intraoperative findings confirmed a ruptured abscess within the left ventricular outflow tract (LVOT).The postoperative course was uneventful, and he completed a six-week course of targeted antimicrobial therapy.This case underscores the importance of prompt diagnosis and early surgical intervention in patients with BAV who develop IE, particularly when complicated by suppurative lesions, and highlights the pathogenic potential of S. anginosus.It also shows that a root-conserving technique was a feasible option in this patient with a mildly dilated aortic root, although its role compared with root replacement cannot be established from a single case.