Infective Endocarditis Caused by Neisseria Sicca Species 10 Years After Mechanical Aortic Valve Implantation

We report a rare case of mechanical aortic valve infective endocarditis caused by Neisseria sicca. A 44-year-old man, with a history of aortic valve replacement, presented to the hospital with a 10-day history of fever. Investigations revealed that the blood cultures grew Neisseria sicca. Although the transthoracic echocardiogram (TTE) was negative, a transesophageal echocardiogram showed a 0.5 cm × 0.3 cm piece of vegetation attached to the aortic valve. After eight weeks of therapy, according to the antibiotic susceptibility test, the patient's blood cultures were negative, and repeat TTE showed no vegetation. This report can offer valuable insights for clinical diagnosis and treatment of Neisseria sicca endocarditis, particularly when selecting sensitive antibiotics.