Staphylococcus epidermidis : Group of bacteria gram positive cocci
Characteristics
- Rarely cause infections in health people .
- Gr + Ve Cocci .
- Non Sporing , Non Motile Cocci
- Opportunistic pathogen.
- Facultative anaerobic .
- Slime layer.
Habitat
- Humans (skin) .
- Always present in hospital environment .
- Survives drying . Tolerant of Salts .
Transmission
- Direct contact
Pathogenesis
- Lower pathogenicity than Staph. Aureus .
- Viscous extracellular slime = Enable the bacteria to adhere to a foreign surface .
Diseases
- Urinary Tract Infection ( UTI )
- Prosthetic valve Endocarditis.
- Bacteremia.
- surgical wounds.
- central nervous system infection.
Laboratory Identification
- White Colonies on Blood Agar
- Catalase +Ve , Coagulase -Ve , DNase – Ve
- Sensitive to Novobiocin disc .
How to differentiate between Staphylococcus epidermidis and Staphylococcus saprophyticus ?
Novobiocin test
Example of the image Staphylococcus epidermidis