Which test is used for confirming the identity of a strain of Staphylococcus aureus?

The coagulase test is specifically employed to confirm the identity of Staphylococcus aureus, making it an essential tool in clinical microbiology. Staphylococcus aureus is characterized by its ability to produce coagulase, an enzyme that causes the coagulation of blood plasma. This distinctive feature sets it apart from other species of Staphylococcus, which do not typically produce this enzyme.

When conducting the coagulase test, a sample of the bacteria is mixed with plasma; if it clots, this indicates the presence of coagulase and confirms that the bacterium is indeed Staphylococcus aureus. This test is particularly valuable in diagnostic settings, helping clinicians quickly identify and manage infections caused by this pathogen.

The other tests mentioned serve different purposes. For example, the Gram stain is useful for identifying the Gram status of bacteria, distinguishing between Gram-positive and Gram-negative organisms, but it does not specifically identify Staphylococcus aureus. The catalase test differentiates Staphylococcus (catalase-positive) from Streptococcus (catalase-negative) but does not confirm the identity of Staphylococcus aureus itself. Oxacillin resistance screening, while important for determining antibiotic susceptibility, also does not directly confirm the identity of St