Neisseria elongata endocarditis of a native aortic valve.

Neisseria elongata is a part of the common bacterial flora of the oropharynx but has caused sepsis, osteomyelitis and infective endocarditis on rare occasions. We report the case of a 56-year-old Caucasian woman who was admitted to hospital with a 5-week history of fever, malaise and fatigue. Two blood cultures grew Gram-negative rods which were confirmed to be N. elongata subspecies nitroreducens via bacterial DNA sequence analysis. An echocardiogram showed a large mobile vegetation on the right and non-coronary cusps of the aortic valve. The patient underwent aortic valve replacement and antibiotic therapy for 6 weeks. We suggest that clinicians should consider extended antibiotic treatment and early surgical evaluation based on the nature and aggressiveness of N. elongata.