The bile solubility test primarily targets which species of Streptococcus?

The bile solubility test is a specific laboratory procedure used to differentiate Streptococcus pneumoniae from other streptococci. This test exploits the unique ability of S. pneumoniae to be lysed in the presence of bile salts, which is not a characteristic of many other streptococcal species.

When bile salts are introduced, S. pneumoniae demonstrates a clear zone of lysis, indicating that it has been effectively broken down. In contrast, other species, such as those included in groups A and B streptococci (Streptococcus pyogenes and Streptococcus agalactiae), do not show this reaction. This characteristic is useful in clinical microbiology for confirming the presence of S. pneumoniae in a sample, making the bile solubility test a targeted approach for identifying this specific pathogen.

Thus, the primary target of the bile solubility test is Streptococcus pneumoniae, as its unique susceptibility to bile salts distinguishes it from other Streptococcus species commonly encountered in clinical settings.