The genus Neisseria consists of commensal species that colonize the mucosal surfaces of many animals. Of the eleven species that colonize humans, only two are pathogens. Neisseria meningitidis and Neisseria gonorrhoeae often cause asymptomatic infections, a commensal-like behavior. Most gonoccocal infections are asymptomatic and self-resolving, and epidemic strains of the meningococcus may be carried in more than 95% of a population where systemic disease occurs at less than 1% prevalence. Bacteria of the Neisseria genus are Gram-negative and are included among the proteobacteria, a large group of Gram-negative organisms. The microorganisms exist as diplococci.

Neisseria gonorrhoeae and Neisseria meningitidis are Gram-negative diplococci. N. gonorrhoeae is the causative agent of gonorrhoea and is transmitted via sexual contact. N. meningitidis is transmitted via respiratory droplets leading to colonization of the nasopharynx and can cause meningitis and septicemia.

1. Neisseria: Molecular Mechanisms of Pathogenesis
2. Microbiology books

Labels: brief notes, diplococci, gonococcus, gonorrhoea, gonorrhoeae, meningitidis, meningococcal, meningococcus, Neisseria, Neisseria gonorrhoeae