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''Gardnerella'' is a genus of Gram-variable-staining facultative anaerobic bacteria of which ''G. vaginalis'' is the only species. The organisms are small (1-1.5 µm diameter) non-spore forming, non-motile coccobacilli. Once classified as ''Haemophilus vaginalis'' and afterwards as ''Corynebacterium vaginalis'', ''Gardnerella vaginalis'' grows as small, circular, convex, gray colonies on chocolate agar; it also grows on HBT agar. A selective medium for ''G. vaginalis'' is colistin-oxolinic acid blood agar. ==Clinical significance== ''Gardnerella vaginalis'' is a facultatively anaerobic Gram-variable rod that is involved, together with many other bacteria mostly anaerobic, in bacterial vaginosis in some women as a result of a disruption in the normal vaginal microflora. The resident facultative anaerobic ''Lactobacillus'' population in the vagina are responsible for the acidic environment. Once the anaerobes have supplanted the normal vaginal bacteria, prescription antibiotics with anaerobic coverage may have to be given to re-establish the equilibrium of the ecosystem and allow the balance to be restored. ''G vaginalis '' is not considered the cause of the bacterial vaginosis, but a signal organism of the altered microbial ecology associated with overgrowth of many bacterial species.〔http://www.emedicinehealth.com/bacterial_vaginosis/article_em.htm〕 While typically isolated in genital cultures, it may also be detected in other samples from blood, urine, and pharynx. Although ''G. vaginalis'' is a major species present in bacterial vaginosis, it can also be isolated from women without any signs or symptoms of infection. It has a Gram-positive cell wall,〔J Harper and G Davis. (Cell Wall Analysis of Gardnerella vaginalis )" ''Int J Syst Bacteriol'' 32 (1982), 48-50.〕 but because the cell wall is so thin it can appear either Gram-positive or Gram-negative under the microscope. It is associated microscopically with clue cells, which are epithelial cells covered in bacteria. ''G. vaginalis'' produces a pore-forming toxin, vaginolysin, which affects only human cells. Protease and sialidase enzyme activities frequently accompany ''G. vaginalis''.〔Lopes dos Santos Santiago, G., P. Deschaght, N. El Aila, T. N. Kiama, H. Verstraelen, K. K. Jefferson, M. Temmerman, and M. Vaneechoutte. 2011. Gardnerella vaginalis comprises three distinct genotypes of which only two produce sialidase. Am. J. Obstet. Gynecol. 204:450.e1-450.e7.〕〔Harwich, M. D., Jr., J. M. Alves, G. A. Buck, J. F. Strauss, 3rd, J. L. Patterson, A. T. Oki, P. H. Girerd, and K. K. Jefferson. 2010. Drawing the line between commensal and pathogenic Gardnerella vaginalis through genome analysis and virulence studies. BMC Genomics 11:375.〕〔von Nicolai, H., R. Hammann, S. Salehnia, and F. Zilliken. 1984. A newly discovered sialidase from Gardnerella vaginalis. Zentralbl. Bakteriol. Mikrobiol. Hyg. A. 258:20-26.〕〔Yeoman, C. J., S. Yildirim, S. M. Thomas, A. S. Durkin, M. Torralba, G. Sutton, C. J. Buhay, Y. Ding, S. P. Dugan-Rocha, D. M. Muzny, X. Qin, R. A. Gibbs, S. R. Leigh, R. Stumpf, B. A. White, S. K. Highlander, K. E. Nelson, and B. A. Wilson. 2010. Comparative genomics of Gardnerella vaginalis strains reveals substantial differences in metabolic and virulence potential. PLOS ONE 5:e12411.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Gardnerella vaginalis」の詳細全文を読む スポンサード リンク
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