Staphylococcus epidermidis

Staphylococcus epidermidis/epidermis
Scanning electron image of S. epidermidis. Scanning electron image of S. epidermidis.
Scientific classification
Kingdom: Bacteria Phylum: Firmicutes Class: Cocci Order: Bacillales Family: Staphylococcaceae Genus: Staphylococcus Species: S. epidermidis
Binomial name
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.It is sensitive to the antibiotic Novobiocin; a feature that distinguishes it from the other common coagulase negative organism Staph. saprophyticus. 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.

The normal practice of detecting S.epidermidis is by using the Baird Parker agar with egg yolk supplement. Colonies appeared in small, black colonies while confirmation can be done using coagulase test.

Antimicrobial therapy

• Bacteremia: most often due to IV lines, vascular grafts, cardiac valves (30-40% of all coagulase-negative staphylococcus infections)

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h AND Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation for Peripheral line is to remove line, antibiotics for 5-7 days and for central line is to may often keep line and systemic antibiotics for 2 wks with antibiotics lock.consider valve replacement and antibiotics for 6 wks.

• CSF shunt: meningitis

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation is

• Peritoneal dialysis catheter: peritonitis

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

• Prosthetic joint: septic arthritis

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation is typically remove joint (two stage more common than single stage replacement), antibiotics for 6 wks. If very early infection (less than 3 wks post-op, debridement and retention an option).

• Prosthetic or natural cardiac valve: endocarditis

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation is

• Post-sternotomy: osteomyelitis

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation is

• Implants (breast, penile, pacemaker) and other prosthetic devices: local infection

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation is

• Post-ocular surgery: endophthalmitis

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation is

• Surgical site infections

• Preferred regimen: Vancomycin 15 mg/kg IV q12h with or without Rifampin 300 mg q8h IV/PO OR Gentamicin 3 mg/kg/day IV q8h added to Vancomycin AND Rifampin 300 mg q8h IV/PO for prosthetic valve IE.
• Alternative regimen (methicillin resistent Staphylococcus epidermidis) (1): Linezolid 600 mg IV/PO bd OR Daptomycin IV 6 mg/kg/day with or without Rifampin 300 mg q8h IV/PO.
• Alternative regimen (methicillin-sensitive Staphylococcus epidermidis) (2): (Oxacillin 1.5-3 g IV q6h OR Nafcillin 1.5-3 g IV q6h), OR Cefazolin 1-2 g IV q8h OR Ciprofloxacin 400 mg IV q12h OR Clindamycin 600 mg IV q8h OR Trimethoprim-Sulfamethoxazole.

Note: site sepcific recommendation is

Note: only assume Methicillin susceptible if multiple isolates are so identified.

Peripheral line: remove line, antibiotics for 5-7 days. Central line: may often keep line and systemic antibiotics for 2 wks with antibiotics lock. Prosthetic joint: typically remove joint (two stage more common than single stage replacement), antibiotics for 6 wks. If very early infection (less than 3 wks post-op, debridement and retention an option). Dialysis catheter: keep catheter (at least for first effort) and IV Vancomycin (usually 2 g IV/wk and redose when level <15 mcg/mL) with antibiotics lock for 10-14 days. Vascular graft: remove graft, antibiotics for 6 wks. CSF shunt: shunt removal usually recommended but variable. Vancomycin 22.5 mg/kg IV q12h and rifampin PO/IV and possible intraventricular antibiotics: Vancomycin 20 mg/day with or without Gentamicin 4-8 mg/day.