Neisseria
N. animalis
N. animaloris
N. bacilliformis
N. canis
N. cinerea
N. dentiae
N. elongata
N. flava
N. flavescens
N. gonorrhoeae
N. iguanae
N. lactamica
N. macacae
N. meningitidis
N. mucosa
N. oralis
N. perflava
N. pharyngis
N. polysaccharea
N. shayeganii
N. sicca
N. subflava
N. wadsworthii
N. weaveri
N. zoodegmatis
Neisseria is a large genus of bacteria that colonize the mucosal surfaces of many animals. Of the 11 species that colonize humans, only two are pathogens, N. meningitidis and N. gonorrhoeae. Most gonococcal infections are asymptomatic and self-resolving, and epidemic strains of the meningococcus may be carried in >95% of a population where systemic disease occurs at <1% prevalence.
Neisseria species are Gram-negative bacteria included among the proteobacteria, a large group of Gram-negative forms. Neisseria diplococci resemble coffee beans when viewed microscopically.[1]
Species of this genus (family Neisseriaceae) of parasitic bacteria grow in pairs and occasionally tetrads, and thrive best at 98.6 °F (37 °C) in the animal body or serum media.
These two species have the ability of 'breaching' the barrier. Local cytokines of the area become secreted to initiate an immune response. However, neutrophils are not able to do their job due to the ability of Neisseria to invade and replicate within neutrophils, as well avoiding phagocytosis and being killed by complement by resisting opsonization by antibodies, which target the pathogen for destruction. Neisseria species are also able to alter their antigens to avoid being engulfed by a process called antigenic variation, which is observed primarily in surface-located molecules. The pathogenic species along with some commensal species, have type IV pili which serve multiple functions for this organism. Some functions of the type IV pili include: mediating attachment to various cells and tissues, twitching motility, natural competence, microcolony formation, extensive intrastrain phase, and antigenic variation.
Neisseria bacteria have also been shown to be an important factor in the early stages of canine plaque development.[2]
