Staphylococcus epidermidis

This Gram positive coccus is found as pairs, tetrads, and irregular, grape-like clusters. Cells are catalase positive and exhibit facultatively anaerobic metabolism. Able to use glucose oxidatively and fermentatively. Salt tolerant in media with NaCl concentrations up to 7.5%. Growth occurs at temperatures between 15-45 C, with optimum growth occurring between 30-37 C. Isolated most frequently from the skin of humans and other mammals. It can be pathogenic in immunocompromised hosts, often causing nosocomial infections related to indwelling medical devices.