Bacteremia Caused by Neisseria elongata in an Infective Endocarditis Patient: Case Report and Review of Literature

Background: Neisseria elongata (N. elongate) is a strictly aerobic and gram-negative rod bacterium which is a constituent of the commensal bacterial flora in the pharynx. Infection caused by Neisseria elongata is rarely reported. Here we describe a case of endocarditis in a patient after aortic mechanical valve replacement caused by N. elongate in China. Method: A 30-year-old man suffered infective endocarditis after aortic mechanical valve replacement. Blood cultures were positive and the organism was identified as Neisseria elongata by MALDI-TOF MS as well as the 16S rRNA sequencing. Result: The patient was treated with ofloxacin and meropenem. He was successfully treated with the 6-week course of antibiotic therapy. Conclusions: N. elongate endocarditis is rarely reported. Our report expands the range of infection caused by N. elongate.