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| __NOTOC__
| | #REDIRECT[[Gardnerella vaginalis]] |
| {{Taxobox
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| | color = lightgrey
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| | name = ''Gardnerella''
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| | regnum = [[Bacterium|Bacteria]]
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| | phylum = [[Actinobacteria]]
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| | ordo = [[Bifidobacteriales]]
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| | familia = [[Bifidobacteriaceae]]
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| | genus = '''''Gardnerella'''''
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| | species = '''''G. vaginalis'''''
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| | binomial = ''Gardnerella vaginalis''
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| | binomial_authority = ([[George Gardner|Gardner]] and Dukes 1955) Greenwood and [[Fermen Layton Pickett|Pickett]] 1980
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| }}
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| {{SI}}
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| {{CMG}};
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| == Overview ==
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| '''Gardnerella''' is a [[genus]] of [[Gram staining|gram-variable]] [[bacteria]] of which '''Gardnerella vaginalis''' is the only species. Gardnerella vaginalis can cause [[bacterial vaginosis]] in some women.
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| ==Microbiology==
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| Gardnerella vaginalis, formerly known as Haemophilus vaginalis and Corynebacterium vaginale, is a facultative [[anaerobic]], nonmotile, pleomorphic [[gram-negative]] to [[gram-variable]] rod bacteria. It is a well-recognized colonizer of the female [[genital tract]] and survives high [[pH]].<ref name="pmid1624577">{{cite journal| author=Smith SM, Ogbara T, Eng RH| title=Involvement of Gardnerella vaginalis in urinary tract infections in men. | journal=J Clin Microbiol | year= 1992 | volume= 30 | issue= 6 | pages= 1575-7 | pmid=1624577 | doi= | pmc=265332 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1624577 }} </ref>
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| It also survives poorly in human urine at 37 degrees C.<ref name="pmid1992615">{{cite journal| author=Lam MH, Birch DF| title=Survival of Gardnerella vaginalis in human urine. | journal=Am J Clin Pathol | year= 1991 | volume= 95 | issue= 2 | pages= 234-9 | pmid=1992615 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1992615 }} </ref>
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| G. vaginalis was first recognized by Leopold and named Haemophilus vaginalis by Gardner and Dukes in 1955 because it was isolated on human blood bilayer agar media.<ref name="pmid1498765">{{cite journal| author=Catlin BW| title=Gardnerella vaginalis: characteristics, clinical considerations, and controversies. | journal=Clin Microbiol Rev | year= 1992 | volume= 5 | issue= 3 | pages= 213-37 | pmid=1498765 | doi= | pmc=358241 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1498765 }} </ref>
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| This method of isolation did not yield great amounts of bacteria and therefore, was introduced with Tween 80 (HBT medium) or without Tween 80 (HB medium). HB medium consists of a basal layer of Columbia agar base containing colistin and naladixic acid with added amphotericin B and an overlayer of the same composition plus 5% human blood. HBT agar also contains Proteose Peptone No. 3 (Difco Laboratories) and Tween 80 in the basal layer and the overlayer. Both Tween 80 and the bilayer composition enhanced G. vaginalis production of human blood [[hemolysis]], permitting detection of this organism even in the presence of heavy growth of other vaginal flora. G. vaginalis is resistant to [[lactobacillus]] and many antibiotics such as [[tetracycline]]. Thus, it is important to sequence its genome to find out what makes it resistant and what genes are expressed in the genome that makes it resistant.<ref name=Isolation-of-Gardnerella> Totten PA, R Amsel, J Hale, PPiot, KK Holmes. "Selective differential human blood bilayer media for isolation of Gardnerella (Haemophilus) vaginalis." J Clin Microbiol. 1982 Jan ;15 (1):141-7</ref>
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| ==Genome structure==
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| The Gardnerella vaginalis [[genome]] is a circular DNA that ranges between 1.67 Mb and 1.72 Mb in size, with a 42-44% G+C content.<ref name="pmid7584037">{{cite journal| author=Lim D, Trivedi H, Nath K| title=Determination of Gardnerella vaginalis genome size by pulsed-field gel electrophoresis. | journal=DNA Res | year= 1994 | volume= 1 | issue= 3 | pages= 115-22 | pmid=7584037 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7584037 }} </ref>
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| It is obvious that it codes for genes that help it adhere to [[epithelial cells]] and proliferate despite in the presence of [[lactobaccilus]] (probiotics) and [[antibiotics.]] Due to the difficulties experienced in lysing the microbe, the investigations have been limited. No plasmids have been discovered yet but a procedure described by a few researchers for isolating DNA should facilitate restriction e[[ndonuclease]] analyses of choromosomal DNA from clinical isolates and exploration for extrachromosomal [[plasmids]].<ref name="pmid1498765">{{cite journal| author=Catlin BW| title=Gardnerella vaginalis: characteristics, clinical considerations, and controversies. | journal=Clin Microbiol Rev | year= 1992 | volume= 5 | issue= 3 | pages= 213-37 | pmid=1498765 | doi= | pmc=358241 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1498765 }} </ref>
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| ===Cell structure and metabolism===
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| Gardnerella vaginalis is a gram-variable microbe, and therefore displays both, [[gram-negative]] and [[gram-positive]] bacteria characteristics. When analyzing its [[culture]], it may appear gram positive during the exponential growth phase but gram negative as it ages because peptidoglycan layer becomes too thin to retain the crystal-violet iodine aggregates.<ref name="pmid1498765">{{cite journal| author=Catlin BW| title=Gardnerella vaginalis: characteristics, clinical considerations, and controversies. | journal=Clin Microbiol Rev | year= 1992 | volume= 5 | issue= 3 | pages= 213-37 | pmid=1498765 | doi= | pmc=358241 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1498765 }} </ref>
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| These organisms are surrounded by an exopolysaccharide layer and [[pili]] that aid in adhering to the [[epithelial cells]] of the [[vagina]]. The cell wall is comprised of straight chain saturated and unsaturated non-hydroxylated fatty acids with hexadecanoic acid and octadecenoic acid along with major amounts of [[alanine]], [[glycine]], [[glutamic acid]] and [[lysine]].<ref name="pmid6611140">{{cite journal| author=O'Donnell AG, Minnikin DE, Goodfellow M, Piot P| title=Fatty acid, polar lipid and wall amino acid composition of Gardnerella vaginalis. | journal=Arch Microbiol | year= 1984 | volume= 138 | issue= 1 | pages= 68-71 | pmid=6611140 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6611140 }} </ref>
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| G. vaginalis has a very complex [[metabolism]]. Gardnerella vaginalis are facultative anaerobes, which means that they can metabolism glucose (and other simple sugars) in under both aerobic and anaerobic conditions. Under both, aerobic and anaerobic metabolism of glucose, G. vaginalis forms [[lactic acid]].
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| ===Pathology===
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| G. vaginalis is one of few microorganisms that are found in women diagnosed with [[bacterial vaginosis]]. They are found in humans and some animals such as mares, and horses. Apart from the [[urinary tract]] and the [[bladder]], they are also found in the [[endometrium]], [[fetal membranes]], and newborn infants and are caused by maternal infections, neonatal infections, and suppurative lesions. It can also be transmitted through sexual intercourse.<ref name="pmid1498765">{{cite journal| author=Catlin BW| title=Gardnerella vaginalis: characteristics, clinical considerations, and controversies. | journal=Clin Microbiol Rev | year= 1992 | volume= 5 | issue= 3 | pages= 213-37 | pmid=1498765 | doi= | pmc=358241 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1498765 }} </ref>
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| Gardnerella vaginalis attaches better to urogenital [[squamous epithelial cells]] due to the exopolysaccharide layer and [[pili]]. It forms biofilms that are resistant to antibiotic treatment and induce inflammatory processes that displace indigenous lactobacilli from its habitat.<ref name="pmid6611140">{{cite journal| author=O'Donnell AG, Minnikin DE, Goodfellow M, Piot P| title=Fatty acid, polar lipid and wall amino acid composition of Gardnerella vaginalis. | journal=Arch Microbiol | year= 1984 | volume= 138 | issue= 1 | pages= 68-71 | pmid=6611140 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6611140 }} </ref>
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| This attachment provides a means of migration from the genitourinary tract to the primary colonization site in the bladder. Women have squamous cells in their genitourinary and their bladder and these cells are absent in a man's bladder, therefore, they are less susceptible to this pathogen.<ref name="pmid1498765">{{cite journal| author=Catlin BW| title=Gardnerella vaginalis: characteristics, clinical considerations, and controversies. | journal=Clin Microbiol Rev | year= 1992 | volume= 5 | issue= 3 | pages= 213-37 | pmid=1498765 | doi= | pmc=358241 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1498765 }} </ref>
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| The presence of clue cell-like squamous epithelial cells are observed in bladder urine by suprapubic aspiration in women affected with G. vaginalis and none are observed in men. Overall there is little information concerning the pathogenic mechanisms of G. vaginalis. G. vaginalis secretes a 60-kDa hemolysin which lyses human erythrocytes, neutrophils, and endothelial cells and thus, is a potential virulence factor.<ref name="pmid9746616">{{cite journal| author=Jarosik GP, Land CB, Duhon P, Chandler R, Mercer T| title=Acquisition of iron by Gardnerella vaginalis. | journal=Infect Immun | year= 1998 | volume= 66 | issue= 10 | pages= 5041-7 | pmid=9746616 | doi= | pmc=108627 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9746616 }} </ref>
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| Some symptoms associated with vaginosis in women caused by G. vaginalis may include Gray, foul smelling vaginal discharge (the smell is particularly noticeable after intercourse, because semen is alkaline and reacts with the bacteria, causing the release of chemicals that produce the fishy smell), may have vaginal itching or burning, may have burning or discomfort on urination, and may have pain with sexual intercourse.<ref name="pmid1498765">{{cite journal| author=Catlin BW| title=Gardnerella vaginalis: characteristics, clinical considerations, and controversies. | journal=Clin Microbiol Rev | year= 1992 | volume= 5 | issue= 3 | pages= 213-37 | pmid=1498765 | doi= | pmc=358241 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1498765 }} </ref>
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| Men may not have physical symptoms.
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| [[Image:Clue_cells_(Gardnerella_Vaginalis).jpg|thumb|center|Clue cells (Gardnerella Vaginalis)]]
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| ====Reactions====
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| Infections with ''G. vaginalis'' go along with [[proteolysis]], giving nitrous products such as [[cadaverine]]s and [[putrescine]]s, which can cause a bad smell and loss of water.
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| == References ==
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| {{reflist|2}}
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| [[es:Gardnerella vaginalis]]
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| [[fr:Gardnerella vaginalis]]
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| [[Category:Actinobacteria]]
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| [[Category:Bacteria]]
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