|Molar mass||340.46 g/mol|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Optochin (or ethylhydrocupreine) is a chemical used in cell culture techniques for the presumptive identification of Streptococcus pneumoniae, which is optochin-sensitive, from other alpha-hemolytic streptococci such as Streptococcus viridans, which are resistant. A common mnemonic is "OVRPS" (Optochin - Viridans [are] Resistant, Pneumoniae [are] Sensitive). Or "VROPS" (Viridans Resistant [to] Optochin, Pneumoniae Sensitive)
The growth of Bacteria that are optochin-sensitive will be inhibited around an optochin disc, while the growth of bacteria that are optochin-resistant will not be affected. In vitro, a solution of as little as 1:10,000,000 may be inhibitory to the pneumococcus, and 1:500,000 is bactericidal.
Strains of Streptococcus viridans have been found to be resistant to optochin in laboratory testing.
- Pikis A, Campos JM, Rodriguez WJ, Keith JM (2001), "Optochin resistance in Streptococcus pneumoniae: mechanism, significance, and clinical implications", Journal of Infectious Diseases 184 (5): 582–590, doi:10.1086/322803, PMID 11474432