[Comparison of various methods for the identification of pneumococci based on optochin sensitivity]

The sensitivity against optochin of 491 strains of Streptococcus pneumoniae respectively alpha-haemolytic Streptococci was tested in optochin-plate-method and in the diffusion-test. Discs impregnated and used in wet condition and dry discs prepared in one of the participating laboratories were equal in their efficiency. The differentiation of Streptococcus pneumoniae and alpha-haemolytic Streptococci is possible by the disc-diffusion method using the following limit of inhibition zone. Streptococcus pneumoniae diameter of inhibition zone greater than 15 mm alpha-haemolytic Streptococci diameter of inhibition zone 0-15 mm The industrial production of optochin-discs can be recommended.