Staphylococcus epidermidis
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Staphylococcus epidermidis/epidermis |
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Scanning electron image of S. epidermidis.
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Scientific classification | ||||||||||||||
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Staphylococcus epidermidis (Winslow & Winslow 1908) Evans 1916 |
Staphylococcus epidermidis is a member of the bacterial genus Staphylococcus, consisting of Gram-positive cocci arranged in clusters. It is catalase-positive and coagulase-negative and occurs frequently on the skin of humans and animals and in mucous membranes. Due to contamination, S. epidermidis is probably the most common species found in laboratory tests.
Although S. epidermidis is usually non-pathogenic, it is an important cause of infection in patients whose immune system is compromised, or who have indwelling catheters. Many strains produce a slime (biofilm) that allows them to adhere to the surfaces of medical prostheses.
S. epidermidis is often resistant to a wide variety of antibiotics, including penicillin and methicillin.
Colonies of S. epidermidis are typically small, white or beige, approximately 1-2 mm in diameter after overnight incubation. The organism is sensitive to desferrioxamine, and this test is used to distinguish it from almost all other staphylococci. Staphylococcus hominis, which is also sensitive, produces acid from trehalose, so it can usually be distinguished from S. epidermidis.
[edit] References
- Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0-8385-8529-9.