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.

Neisseria elongata subsp elongata infective endocarditis following endurance exercise.

A 31-year-old Argentinian woman presented with a 3-week history of fever, night sweats, myalgia and lethargy following a work trip to Uganda where she ran a marathon. Malarial screens were negative but C reactive protein, erythrocyte sedimentation rate and neutrophil count were raised and she was anaemic. A new pansystolic murmur was heard over the mitral valve and the transthoracic echocardiogram showed a large vegetation (>1 cm) with at least moderate mitral regurgitation. Blood cultures grew Neisseria elongata, subsp elongata treated initially with ceftriaxone then oral ciprofloxacin to complete 4 weeks of treatment. CT scan revealed a wedge-shaped area of low attenuation in the spleen in keeping with a splenic infarct. Seven days postadmission, the patient underwent a successful mitral valve repair. Recovery was complicated by a likely embolic infarct in the right frontal lobe, but the patient was discharged 12 days postoperative with no neurological sequelae.

[Isolation of Neisseria elongata subsp. elongata Isolated from an Acute Myelogenous Leukemia Patient].

Gram-negative cocci with a rod-like shape were isolated from a blood sample of a patient with acute myelogenous leukemia (AML). The 16S rRNA sequence of the isolate was similar to that of Neisseria elongata. Because previous reports about N. elongata as a pathogen have been extremely rare, more reliable identification seemed to be needed. We thus additionally performed a Multilocus Sequencing Analysis (MLSA) based on another four regions (argF, rho, recA, glnA), and confirmed the identification of N. elongata. The results from the MLSA identified the species; however, we could not identify the isolates into subspecies from the sequences. Three subspecies of N. elongata (N. elongata subsp. elongata, N. elongata subsp. glycolytica and N. elongata subsp. nitroreducens) were classified based on three definitive characteristics (catalase possession, nitrite reducibility, and acid from glucose). The results of the tests of three characteristics supported the identification of the isolate as N. elongata subsp. elongata. Therefore we determined the isolate from the AML patient to be N. elongata subsp. elongata.

Infective endocarditis caused by Neisseria elongata on a native tricuspid valve and confirmed by DNA sequencing.

Neisseria elongata, a common oral bacterium, has been recognized as a cause of infections such as infective endocarditis, septicemia, and osteomyelitis. Neisseria-induced infective endocarditis, although infrequently reported, typically arises after dental procedures. Without antibiotic therapy, its complications can be severe. We report the case of a 27-year-old man who presented with fever, severe dyspnea, and a leg abscess from cellulitis. An echocardiogram showed a vegetation-like echogenic structure on the septal leaflet of the patient's native tricuspid valve, and an insignificant Gerbode defect. Three blood cultures grew gram-negative, antibiotic-susceptible coccobacilli that were confirmed to be N. elongata. Subsequent DNA sequencing conclusively isolated N. elongata subsp nitroreducens as the organism responsible for the infective endocarditis. The patient recovered after 21 days of antibiotic therapy. In addition to the patient's unusual case, we discuss the nature and isolation of N. elongata and its subspecies.

Prosthetic valve endocarditis due to Neisseria elongata subsp. elongata in a patient with Klinefelter's syndrome.

A case is reported of prosthetic valve endocarditis due to Neisseria elongata subsp. elongata in a patient with Klinefelter's syndrome. This is believed to be only the third case of endocarditis reported due to this subspecies. N. elongata is difficult to identify, and is morphologically and biochemically similar to Kingella spp. Sequencing of the 16S rRNA gene is useful for identification. The patient was successfully treated with amoxicillin and gentamicin, followed by ceftriaxone.