How is the bile solubility of organisms determined?

The determination of bile solubility of organisms is assessed by their lysis in the presence of sodium deoxycholate. This method is particularly useful in differentiating certain pathogenic bacteria, such as Streptococcus pneumoniae, which is lysed by bile salts. Sodium deoxycholate mimics the effects of bile in the gastrointestinal tract, causing lysis in bile-soluble organisms.

When bacteria are exposed to sodium deoxycholate, bile-sensitive bacteria will lose their structural integrity, leading to cell lysis. This property is specifically associated with a lack of the capsule or the presence of specific cell wall components that allow for this lytic action. As a result, this test is specifically tailored to identify organisms based on their response to bile salts, providing a reliable method for laboratory identification.

The other options presented do not pertain directly to bile solubility. Growth on selective media may indicate the presence of certain types of bacteria but does not address their bile resistance or sensitivity. Similarly, the ability to ferment mannitol is related to metabolic processes and not directly connected to the lytic action of bile salts. Lastly, the Cefinase test assesses an organism's ability to produce beta-lactamase and does not involve bile sol