Staphylococcus epidermidis

Cell structure and metabolism

As a gram-positive bacterium, S. epidermidis has a cell wall made of a large concentration of peptidoglycan layer but no outer membrane. The cell-wall anchored(CWA)proteins of these bacteria are part of a family of surface-exposed proteins that interact with targets in the host. These CWA proteins possess an N-terminal secretion signal sequence (S) required for sec-dependent secretion, followed by a non-repeat A domain that contains the ligand-binding site. These interactions are particular important because they are involved in bacterial adherence and escape from the host defense systems. No mechanism is known to explain the virulence of S. epidermidis, but it is thought that the cell wall proteins are potential factors that must be involved.

S.epidermis requires oxygen to grow, more precisely it is a facultative anaerobe orgnaism. It is non-motile; and has no endospores. Since it is a pathogen of the human skin, S. epidermidis grows best at 37°C (mesophilic), the optimal temperature for the human body.