Optochin sensitivity allows for the presumptive identification of alpha-hemolytic streptococci as S. pneumoniae, although some pneumococcal strains are optochin-resistant. The growth of bacteria that are optochin-sensitive will show a zone of inhibition around an optochin disc, while the growth of bacteria that are resistant to optochin will not be affected. For the optochin susceptibility test, the Optochin impregnated disk is placed on a lawn of organism on a sheep blood agar plate, allowing the … 1957;49:641–642.Isenberg H D, editor. It has been known, since the turn of the century, when optochin (ethylhydrocupreine hydrochloride) was first synthesized, to inhibit the growth of Streptococcus pneumoniae 2). Optochin (or ethylhydrocupreine hydrochloride) is a derivative of hydroquinine introduced in 1911 by Morgenroth and Levy with the intention to treat pneumococci infection. Optochin also known as ethylhydrocupreine hydrochloride, is currently widely used as an inexpensive and reliable means to presumptively identify Streptococcus pneumoniae 1). Journal of Clinical Pathology. 1955;8(1):58–60. Additionally, it is not categorized according to one of the Lancefield groupings ( Songer and Post, 2005 ). In very high dilutions inhibits the growth of representatives of all four groups of pneumococci in vitro. J Lab Clin Med. 1.20.25–1.20.26.Austrian R, Collins P. Importance of carbon dioxide in the isolation of pneumococci. Optochin also known as ethylhydrocupreine hydrochloride, is currently widely used as an inexpensive and reliable means to presumptively identify Streptococcus pneumoniae,The current National Committee for Clinical Laboratory Standards (NCCLS) guidelines regarding optochin inhibition recommend using a “blood agar plate,” specifying neither the type of blood nor the type of agar.A presumptive identification for Streptococcus pneumoniae can be made if the alpha-hemolytic colony produces a zone of inhibition of 14 mm or greater around the disk. Organisms with questionable zone sizes (6-14 mm) around the disk should be presumptively identified as a pneumococci only if it is bile soluble.Burckhardt I, Panitz J, Burckhardt F, Zimmermann S. Identification of Streptococcus pneumoniae: Development of a Standardized Protocol for Optochin Susceptibility Testing Using Total Lab Automation. That is the main reason it is now used in bacteriology for the differentiation of Streptococcus pneumoniae, which is optochin-sensitive, from the other, resistant alpha-hemolyticstreptococci, sometimes called the viridans streptococci becau… We truly appreciate your support.Get instant definitions for any word that hits you anywhere on the web!https://www.definitions.net/definition/optochin. Washington, D.C: American Society for Microbiology; 1992. pp. 1915;22:269–285.Bowers E. F., Jeffries L. R. Optochin in the identification of Str. In vitro, a minimum inhibitory concentration (MIC) of 1:10,000,000 will inhibit the growth of pneumococci, and 1:500,000 is bactericidal.The numerical value of optochin in Chaldean Numerology is:The numerical value of optochin in Pythagorean Numerology is:We're doing our best to make sure our content is useful, accurate and safe.Thanks for your vote! It is useful in the identification of Streptococcus pneumoniae, the alpha-hemolytic Streptococcus most commonly susceptible to this chemical. Optochin revisited: defining the optimal type of blood agar for presumptive identification of Streptococcus pneumoniae. Optochin (or ethylhydrocupreine hydrochloride) is a derivative of hydroquinine introduced in 1911 by Morgenroth and Levy with the intention to treat pneumococci infection. J Exp Med. Optochin is a chemical, ethylhydrocupreine hydrochloride and is completely soluble in water. In very high dilutions inhibits the growth of representatives of all four groups of pneumococci in vitro. Optochin (or ethylhydrocupreine hydrochloride) is a derivative of hydroquinine introduced in 1911 by Morgenroth and Levy with the intention to treat pneumococci infection. S. pneumoniae is an α-hemolytic streptococcus that ferments trehalose and is optochin-sensitive (Harkness and Wagner, 1995; Keyhani and Naghshineh, 1974; Songer and Post, 2005).