From the Guidelines
Staphylococcus (Staph) bacteremia is most commonly caused by infections related to intravascular devices, particularly central venous catheters (CVCs) and peripheral venous catheters.
Normal Sources of Infection
The normal sources of infection with Staph bacteremia include:
- Intravascular devices: Such as CVCs, peripheral venous catheters, and implantable devices, which can become colonized with microorganisms, including coagulase-negative staphylococci and S. aureus 1.
- Skin: The skin is a common source of colonization for CVCs, and microorganisms can enter the catheter through the skin at the site of insertion 1.
- Hematogenous seeding: In some cases, Staph bacteremia can occur through hematogenous seeding of the catheter tip, where microorganisms enter the bloodstream through another source and then colonize the catheter 1.
- Catheter hub and lumen: Contamination of the catheter hub and intraluminal infection is a common route of infection for tunneled CVCs or implantable devices 1.
Common Organisms
The most common organisms associated with CVC infection and Staph bacteremia are:
- Coagulase-negative staphylococci: Such as Staphylococcus epidermidis 1.
- S. aureus: Which is often associated with a higher mortality rate and more severe infections 1.
- Other organisms: Such as Corynebacterium, Bacillus species, and fungi, including Candida species 1. It is essential to note that the likelihood of a CVC being the source of bacteremia depends on the organism cultured, with S. aureus being more likely to be associated with CVC infection than other organisms 1.
From the Research
Normal Sources of Infection with Staphylococcus (Staph) Bacteremia
- The normal sources of infection with Staphylococcus (Staph) bacteremia include:
- Endovascular sources, such as catheter-related bloodstream infections 2, 3, 4
- Prosthetic devices, which can increase the risk of clinically significant bacteremia in immunocompromised patients 2, 5
- Unknown sources, which can be associated with Staphylococcus pettenkoferi bacteremia 3
- Complicated infections, such as metastatic infections, which can be caused by Staphylococcus aureus 5, 4
- The time to positivity in Staphylococcus aureus bacteremia may provide useful diagnostic and prognostic information, with a time to positivity of ≤14 hours being an independent predictor of an endovascular source of infection, extended bacteremia, metastatic infection, and attributable mortality 4
- Staphylococcus pettenkoferi is a relatively recently described coagulase-negative staphylococci species that can cause bacteremia, particularly in patients with catheter-related bloodstream infections or prosthetic devices 2, 3, 6