Neisseria gonorrhoeae
Cultural characteristics
Biochemical characters
Phylum Proteobacteria, Class Betaproteobacteria, Order Neisseriales, Family Neisseriaceae, Genus Neisseria, Neisseria gonorrhoeae
(Zopf 1885) Trevisan 1885 - type species of the genus. Common name: "gonococcus".

Old synonyms:
Micrococcus der gonorrhoe Neisser 1879, Merismopedia gonorrhoeae Zopf 1885, Micrococcus gonorrhoeae (Zopf 1885)
Flugge 1886,
Micrococcus gonococcus Schroeter 1886, Diplococcus gonorrhoeae (Zopf 1885) Lehmann and Neumann 1896,
Gonococcus neisseri Lindau 1898.
Gram-negative cocci, grouped in pairs. Non-motile. Flagella are absent. Capsule is not produced, but produce an extracellular
polyphosphate that may serve the function of a capsule. Fimbriae (pilli) are present.
Isolated from human mucous membrane surfaces. May produce bacteriocins. Resistant to colistin. Some strains are susceptible to
vancomycin and, consequently, may not grow on selective media. Susceptible to unfavorable environmental factors such as
desiccation, heating or chilling, the action of autolytic enzymes, and acid and alkaline conditions.
Human pathogen. Primarily found in gonorrhea (purulent venereal discharges), oropharyngeal infection, endometritis, conjunctivitis,
anorectal infection, and disseminated gonococcal infection. Also found in blood, the conjunctiva, petechiae, pharynx, and
cerebrospinal fluid.

N. gonorrhoeae and N. meningitidis possess several outer membrane proteins that have been studied at the molecular level and
found to be analogous to one another.

N. gonorrhoeae and N. meningitidis pilli are antigenically and structurally similar. Pili mediate the attachment to a wide range of cell
types, including tissue culture cells, vaginal epithelial cells, fallopian tube epithelium, and buccal epithelial cells.

Produce IgA1-protease, which degrades and inactivates immunoglobulin of the IgA1 subtype found in mucosal secretions and serum.
  1. Tone Tonjum, 2005. Order IV. Neisseriales ord. nov. In: Bergey’s Manual of Systematic Bacteriology, Second edition, Vol two, part C
    The Alpha-, Beta-, Delta-, and Epsilonproteobacteria, George M. Garrity (Editor-in-Chief), pp 774-863.
  2. Daniel C. Stein, 2006. The Neisseria. In: The Prokaryotes Third Edition, Volume 5: Proteobacteria:Alpha and Beta Subclasses,
    Martin Dworkin (Editor-in-Chief), pp 602-647.
  3. Magnus Unemo (Editor-in-Chief), 2013. Laboratory diagnosis of sexually transmitted infections, including human immunodeficiency
    virus, pp 44-45. World Health Organization, ISBN 978 92 4 150584 0.
Positive results for catalase, oxidase, acid production from glucose.

Negative results for DN-ase, beta-galactosidase (ONPG), iodine test (polysaccharide synthesis), nitrate reduction, tributyrin hydrolysis,
acid production from: fructose, lactose, maltose, mannose & sucrose.

Nitrite is toxic to
N. gonorrhoeae, so that the reduction of nitrite is only observed at low concentration.
(c) Costin Stoica
Culture media
Biochemical tests
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Primary isolation is made on chocolate agar at temperatures of 35–36 ºC under an
atmosphere containing 3-10% CO
2 and high relative humidity. Minimum growth  
temperature is 30 ºC. Colonies after 48 hours are 0.6-1.0 mm in diameter, opaque,
grayish-white, raised, finely granular, glistening, and convex. They become mucoid if  
incubation is prolonged.  Agglutinating and aggregating cells may result in various
forms of colony consistency  and edge, as well as spreading and/or corroding growth.
Does not resist in old cultures (autolysis) or to prolonged passages.
Fastidious. Requires glutamine for primary isolation of approximately 20% of strains
and co-carboxylase for 1% of strains. Cystine and iron are an essential growth factors.
Sugars fermentation should be tested in cysteine trypticase agar containing sugars
(glucose, maltose, sucrose etc.) at a final concentration of 1-2%.