Association of an important Neisseria species, Neisseria elongata subsp. nitroreducens, with bacteremia, endocarditis, and osteomyelitis.

We retrospectively analyzed epidemiologic information associated with 22 cultures of Neisseria elongata subsp. nitroreducens (formerly CDC group M-6) submitted to the Microbial Diseases Laboratory, California Department of Health Services, Berkeley, over a 16-year period. The most common illnesses noted with this bacterium were endocarditis, bacteremia, and osteomyelitis. Risk factors associated with N. elongata subsp. nitroreducens infection included dental manipulations and/or a previous history of endocarditis, valve damage, or rheumatic heart disease.