<i>Staphylococcus, Micrococcus</i>, and Other Catalase-Positive Cocci
Luis M. de la Maza, Marie T. Pezzlo, Cassiana E. Bittencourt, Ellena M. Peterson
Abstract
Members of the genera Staphylococcus, Micrococcus, Kocuria, and Kytococcus are characterized as being catalase-positive, Gram-positive cocci that occur in pairs and clusters. An important virulence property of Coagulase-negative staphylococci is their ability to form a biofilm on the surface of indwelling or implanted devices, making them frequent agents of intravascular infections. S. aureus can be beta-hemolytic, and it is not uncommon to see both large and small colonies in the same culture, a phenotypic characteristic shared by several heteroresistant methicillin-resistant S. aureus strains. While biochemical tests are still commonly used to identify strains of Staphylococcus to the species level, matrix-assisted laser desorption ionization-time of flight mass spectrometry is rapidly replacing traditional biochemical algorithms. Micrococci, in addition to forming pairs and clusters, can appear as tetrads.