The Neisseriaceae are a family of ''

Pseudomonadota Pseudomonadota (synonym "Proteobacteria") is a major phylum of gram-negative bacteria. Currently, they are considered the predominant phylum within the domain of bacteria. They are naturally found as pathogenic and free-living (non- parasitic) ...

'', within the ''

Neisseriales The Neisseriaceae are a family of '' Pseudomonadota'', within the '' Neisseriales'' order of ''Betaproteobacteria''. While many organisms in the family are mammalian commensals or part of the normal flora, the genus '' Neisseria'' includes two i ...

'' order of ''

Betaproteobacteria ''Betaproteobacteria'' are a class of Gram-negative bacteria, and one of the six classes of the phylum '' Pseudomonadota'' (synonym Proteobacteria). Metabolism The ''Betaproteobacteria'' comprise over 75 genera and 400 species. Together, they ...

''. While many organisms in the family are mammalian

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit f ...

s or part of the normal

flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...

, the genus ''

Neisseria ''Neisseria'' is a large genus of bacteria that colonize the mucous membranes of many animals. Of the 11 species that colonize humans, only two are pathogens: '' N. meningitidis'' and '' N. gonorrhoeae''. ''Neisseria'' species are Gram-negative ...

'' includes two important human pathogens, specifically those responsible for

gonorrhea Gonorrhoea or gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium ''Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Gonorrhea is spread through sexual c ...

(caused by'' N. gonorrhoeae'') and many cases of

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasion ...

("meningococcal meningitis", caused by'' N. meningitidis''). As a group, the ''Neisseriaceae'' are strictly

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cellu ...

and

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

, occur mainly in pairs (

diplococci Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archaea ...

), and typically do not have

flagella A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

References

Bacteria of Medical Importance
in ''Todar's Online Textbook of Bacteriology''. * * {{Authority control Betaproteobacteria