Infective Endocarditis Caused by Staphylococcus lugdunensis

Abstract

Staphylococcus lugdunensis, a minor species of coagulase-negative staphylococci, has attracted attention because of its formidable pathogenicity. We present a case of infective endocarditis (IE) caused by S. lugdunensis in a 72-year-old woman with a history of breast cancer and metastases who presented with fever. Two of two blood culture bottles were positive for gram-positive cocci. Transesophageal echocardiography revealed vegetation attached to the right cusp of the aortic valve and an abscess in the annulus, which was less evident on transthoracic echocardiography. This case underscores the importance of considering S. lugdunensis as a potential cause of IE.

Keywords: Staphylococcus lugdunensis; infective endocarditis; transesophageal echocardiography.

Figure.

Transthoracic echocardiography demonstrates thickened aortic valves and severe aortic stenosis (A, B). Cardiac CT fails to provide a detailed assessment of the aortic valve and surrounding structures due to severe calcification (C, D). However, on transesophageal echocardiography, an aortic annular abscess (E, arrowheads) and vegetation attached to the right cusp of the aortic valve (E, arrow) are clearly visible.