Neisseria elongata sp.nov., a Rod-shaped Member of the Genus Neisseria. Re-evaluation of Cell Shape as a Criterion in Classification

Abstract

A rod-shaped, non-motile, Gram-negative, oxidase-positive and asaccharolytic organism found in the human nasopharynx is allotted to genus Neisseria and named Neisseria elongata. The strain M 2, which is the only isolate, is proposed as the type strain. The average guanine + cytosine (G + C ) content of its DNA is 53 mole yo. Genetic transformation of streptomycin resistance reveals a comparatively high compatibility with N. rneningitidis and a strain designated N. Jlava, with ratios of interstrain to autologous transformation frequency in the range 0.01 to 0.1. On the other hand, there is no affinity in streptomycin-resistance transformation between N . elongata and members of genus Moraxella, including the old concepts N . catarrhalis and N. ovis. The family Neisseriaceae now appears to consist of two genera, Neisseria and Moraxella, each containing both coccal and rod-shaped species, which makes cell shape questionable as a highly weighted criterion in the construction of bacterial genera and higher taxa.

Neisseria bacilliformis sp. nov. Isolated from Human Infections

“…Of the known Neisseria species, N. elongata (of human origin) and N. weaveri (of dog origin and occasionally isolated from human wounds from dog bites) are the only species with a bacillary morphology; all others are cocci or diplococci (2,5,11,13). It has been suggested, therefore, that the diplococcal morphology should not be the sole criterion for the identification of Neisseria (5).…”

Infective Endocarditis Caused by Neisseria elongata on a Native Tricuspid Valve and Confirmed by DNA Sequencing

“…First described by Bovre and Holten in 1970, 7 N. elongata is rarely isolated from clinical specimens. The organism's 3 subspecies are elongata, glycolytica, and nitroreducens.…”

Report (1966-1970) of the Subcommittee on the Taxonomy of the Neisseriaceae to the International Committee on Nomenclature of Bacteria: 14 August 1970

“…This includes descriptions of new species of Neisseria (2,4,11,18,19) and of new serological groups of N. meningitidis (10,12,16,17); genetic, physiological, and structural studies leading to reevaluations of relations between species of Neisseria (8, 9, 14); recommendations that N. catarrhalis be transferred from Neisseria t o another genus (7,9 ) and N. haemolysarzs to another family (1,15); and that Moraxella be included as a genus of Neisseriaceae (9).…”