Pyridoxine-Deficient Streptococcus: An Uncommon Virulent Cause of Subacute Destructive Aortic Valve Endocarditis.

Nutritional variant streptococcus (NVS) or pyridoxal-dependent streptococcus is a rare but significant cause of infective endocarditis (IE), which presents as a diagnostic dilemma due to difficulty in organism isolation, and high rates of treatment failure, recurrence, and mortality. We discuss a case of a 52-year-old male who presented with chronic fatigue, cyclic fever, night sweats, and weight loss. He was treated with culture-directed antibiotics and surgical aortic valve replacement due to disease severity and risk of embolization. This case highlights the clinical significance of NVS IE, and the importance of early recognition, and immediate, often invasive therapy to improve outcomes.