The Gram-positive bacteria Staphylococcus epidermidis and Staphylococcus aureus are the most common pathogens in hospital-acquired infections. The costs related to infections caused by these strains in the hospital setting are enormous and represent a major healthcare burden. Furthermore, the more recent combination of extraordinary virulence and multiple antibiotic resistance in community-acquired methicillin-resistant strains of S. aureus (CA-MRSA) poses an additional severe threat to public health.
S. aureus may cause a multitude of serious infections, including toxic shock and scalded skin syndromes, endocarditis, and pneumonia, to name but a few. In contrast, infections with S. epidermidis are usually chronic and less severe. The most important type of disease caused by S. epidermidis is the colonization and infection of indwelling medical devices.
The outcome of infections with S. epidermidis and S. aureus is closely linked to their interaction with human host defenses. Thus, mechanisms of immune evasion such as the formation of biofilms represent significant virulence determinants in chronic infections with staphylococci.
Credit: Michael Otto, Ph.D.
More about Michael Otto, Ph.D. and his work. (http://www.niaid.nih.gov/labsandresources/labs/aboutlabs/lhbp/pathogenmoleculargeneticssection/Pages/otto.aspx)