- Neisseria gonorrhoeae
Neisseria gonorrhoeae Neisseria gonorrhoeae cultured on two different media types and presented in stereoscopic 3d. Scientific classification Kingdom: Bacteria Phylum: Proteobacteria Class: Beta Proteobacteria Order: Neisseriales Family: Neisseriaceae Genus: Neisseria Species: N. gonorrhoeae Binomial name Neisseria gonorrhoeae
Gonococcus Neisser 1879
Neisseria gonorrhoeae, also known as gonococci (plural), or gonococcus (singular), is a species of Gram-negative coffee bean-shaped diplococci bacteria responsible for the sexually transmitted infection gonorrhea.
N. gonorrhoea was first described by Albert Neisser in 1879.
Neisseria are fastidious Gram-negative cocci that require nutrient supplementation to grow in laboratory cultures. Specifically, they grow on chocolate agar with carbon dioxide. These cocci are facultatively intracellular and typically appear in pairs (diplococci), in the shape of coffee beans. Of the eleven species of Neisseria that colonize humans, only two are pathogens. N. gonorrhoeae is the causative agent of gonorrhea (also called "The Clap," which is derived from the French word "clapier," meaning "brothel") and is transmitted via sexual contact.
Neisseria is usually isolated on Thayer-Martin agar—an agar plate containing antibiotics (Vancomycin, Colistin, Nystatin, and SXT) and nutrients that facilitate the growth of Neisseria species while inhibiting the growth of contaminating bacteria and fungi. Further testing to differentiate the species includes testing for oxidase (all clinically relevant Neisseria show a positive reaction) and the carbohydrates maltose, sucrose, and glucose test in which N. gonorrhoeae will only oxidize (that is, utilize) the glucose.
N. gonorrhoeae are motile (twitching motility) and possess type IV pili to adhere to surfaces. The type IV pili operate mechanistically similar to a grappling hook. Pili extend and attach to a substrate which signals the pilus to retract, dragging the cell forward. N. gonorrhoeae are able to pull 100,000 times their own weight and it has been claimed that the pili used to do so are the strongest biological motor known to date, exerting one nanonewton.
N. gonorrhoeae has surface proteins called Opa proteins, which bind to receptors on immune cells. In so doing, N. gonorrhoeae is able to prevent an immune response. The host is also unable to develop an immunological memory against N. gonorrhoeae – which means that future reinfection is possible. N. gonorrhoeae can also evade the immune system through a process called antigenic variation, in which the N. gonorrhoeae bacterium is able to alter the Opa proteins that adorn its surface. The many permutations of surface proteins make it more difficult for immune cells to recognize N. gonorrhoeae and mount a defense.
N. gonorrhoeae is naturally competent for DNA transformation as well as being capable of conjugation. Both of these concepts allow for the DNA of N. gonorrhoeae the ability to undergo conformational changes. Especially dangerous to the health industry is the ability to conjugate since this can lead to antibiotic resistance.
In 2011, researchers at Northwestern University found evidence of a human DNA fragment in a Neisseria gonorrhoeae genome, the first example of horizontal gene transfer from humans to a bacterial pathogen.
Symptoms of infection with N. gonorrhoeae differ depending on the site of infection. Note also that 10% of infected males and 80% of infected females are asymptomatic.
Conjunctivitis is common in neonates (newborns), and silver nitrate or antibiotics are often applied to their eyes as a preventive measure against gonorrhoea. Neonatal gonorrheal conjunctivitis is contracted when the infant is exposed to N. gonorrhoeae in the birth canal and can lead to corneal scarring or perforation, resulting in blindness in the neonate.
Disseminated N. gonorrhoeae infections can occur, resulting in endocarditis, meningitis or gonococcal dermatitis-arthritis syndrome. Dermatitis-arthritis syndrome presents with arthralgia, tenosynovitis and painless non-pruritic (non-itchy) dermatitis.
Infection of the genitals in females with N. gonorrhoeae can result in pelvic inflammatory disease if left untreated, which can result in infertility. Pelvic inflammatory disease results if N. gonorrhoeae travels into the pelvic peritoneum (via the cervix, endometrium and fallopian tubes). Infertility is caused by inflammation and scarring of the fallopian tube. Infertility is a risk to 10 to 20% of the females infected with N. gonorrhoeae.
Treatment and Prevention
Patients should also be tested for other sexually transmitted infections, especially Chlamydia infections, since co-infection is frequent (up to 50% of cases). Antibacterial coverage is often included for Chlamydia because of this.
Transmission can be reduced by the usage of latex barriers, such as condoms or dental dams, during intercourse, oral and anal sex, and by limiting sexual partners.
- ^ Ryan KJ, Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 0838585299.
- ^ Genco, C; Wetzler, L (editors) (2010). Neisseria: Molecular Mechanisms of Pathogenesis. Caister Academic Press. ISBN 978-1-904455-51-6.
- ^ "Mighty microbe pulls 100,000 times its bodyweight". New Scientist. 19 April 2008. http://www.newscientist.com/article/mg19826525.300-mighty-microbe-pulls-100000-times-its-bodyweight.html. Retrieved 2009-07-01.
- ^ STI Awareness: Gonorrhea. Planned Parenthood Advocates of Arizona. 11 April 2011. Retrieved 31 August 2011.
- ^ "Gonorrhea Acquires a Piece of Human DNA: First Evidence of Gene Transfer from Human Host to Bacterial Pathogen". ScienceDaily.com. 13 February 2011. http://www.sciencedaily.com/releases/2011/02/110213174143.htm. Retrieved 15 February 2011.
- ^ Anderson, Mark T.; H. Steven Seifert (15). "Opportunity and Means: Horizontal Gene Transfer from the Human Host to a Bacterial Pathogen". MBio 2 (1): e00005–11. doi:10.1128/mBio.00005-11. PMC 3042738. PMID 21325040. http://mbio.asm.org/content/2/1/e00005-11.
- ^ http://www.bbc.co.uk/news/health-15238613
Diseases of the skin and appendages by morphology GrowthsPigmentedDermal and
PurpuraMacularthrombocytopenic purpura · actinic purpuraPapularIndurated
Infectious diseases · Bacterial diseases: Proteobacterial G− (primarily A00–A79, 001–041, 080–109) αRickettsia rickettsii (Rocky Mountain spotted fever) · Rickettsia conorii (Boutonneuse fever) · Rickettsia japonica (Japanese spotted fever) · Rickettsia sibirica (North Asian tick typhus) · Rickettsia australis (Queensland tick typhus) · Rickettsia honei (Flinders Island spotted fever) · Rickettsia africae (African tick bite fever) · Rickettsia parkeri (American tick bite fever) · Rickettsia aeschlimannii (Rickettsia aeschlimannii infection)Rickettsia felis (Flea-borne spotted fever)Brucella abortus (Brucellosis) β γH2S-VibrionalesXanthomonadalesCardiobacterialesCardiobacterium hominis (HACEK) ε
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Look at other dictionaries:
Neisseria gonorrhoeae — (Gram Färbung) Systematik Abteilung: Proteobacteria Klasse … Deutsch Wikipedia
Neisseria Gonorrhoeae — Neisseria gonorrhoeae … Wikipédia en Français
Neisseria gonorrhoeae — Neisseria gonorrhoeae … Wikipédia en Français
Neisseria gonorrhoeae — 1. [Albert L. S. Neisser, dermatólogo polaco, n. 1855], diplococo inmóvil gramnegativo, que se presenta al microscopio en forma de parejas aplanadas en el interior del citoplasma de los neutrófilos. Es el microorganismo causante de la gonorrea. 2 … Diccionario médico
Neisseria gonorrhoeae — es un agente etiológico de gonococia, enfermedad de transmisión sexual. Es un diplococo gram negativo, oxidasa positivo. Requiere medios muy nutritivos para el crecimiento, como agar chocolate. Igualmente para su cultivo requiere una atmósfera… … Enciclopedia Universal
Neisseria gonorrhoeae — Neisseria gonorrhoeae … Wikipedia Español
Neisseria gonorrhoeae — В этой статье не хватает ссылок на источники информации. Информация должна быть проверяема, иначе она может быть поставлена под сомнение и удалена. Вы можете … Википедия
Neisseria gonorrhoeae) — В этой статье не хватает ссылок на источники информации. Информация должна быть проверяема, иначе она может быть поставлена под сомнение и удалена. Вы можете … Википедия
Neisseria gonorrhoeae — Neisseria gonorrhoeae … Wikipédia en Français
Neisseria gonorrhoeae — the specific etiologic agent of gonorrhea, occurring typically as pairs of flattened cells, found primarily in purulent venereal discharges … Medical dictionary