Elkare

 Overview of Staphylococcus The genus Staphylococcus consists of Gram-positive, spherical cells (cocci) that characteristically divide in multiple planes to form irregular, grape-like clusters. They are non-motile, non-spore-forming, and typically facultative anaerobes. From a diagnostic perspective, the definitive starting point to differentiate Staphylococcus from Streptococcus is the catalase test, as all clinically significant staphylococci are catalase-positive. Major Clinically Significant Species The genus is broadly categorized into two main groups based on the production of the coagulase enzyme, which clots plasma: 1. Coagulase-Positive Staphylococci (CoPS) Staphylococcus aureus: The most pathogenic species. It produces staphyloxanthin, a carotenoid pigment that gives its colonies a characteristic golden-yellow color on solid media. It is a major cause of both superficial skin infections and deep-seated systemic infections. 2. Coagulase-Negative Staphylococci (CoNS) Staphy...