Most common cause of infection caused by intravascular catheter ?
**Core Concept**
The most common cause of infection caused by intravascular catheters is related to the colonization of the catheter's surface by microorganisms, leading to biofilm formation and subsequent infection. This phenomenon is often associated with the catheter's material, size, and duration of use.
**Why the Correct Answer is Right**
The correct answer is Staphylococcus epidermidis, a coagulase-negative staphylococcus that is commonly found on human skin. This bacterium can colonize the catheter's surface, particularly if the catheter is made of a material that is not well-tolerated by the body, such as silicone or polyurethane. The biofilm formed by S. epidermidis can protect the bacteria from antibiotics and host immune responses, leading to persistent infection.
**Why Each Wrong Option is Incorrect**
* **Option A:** Escherichia coli (E. coli) is a gram-negative rod that can cause urinary tract infections and other types of infections, but it is not the most common cause of catheter-related bloodstream infections.
* **Option B:** Pseudomonas aeruginosa is a gram-negative rod that can cause a variety of infections, including those related to medical devices, but it is less commonly associated with catheter-related infections than S. epidermidis.
* **Option C:** Staphylococcus aureus is a coagulase-positive staphylococcus that can cause a range of infections, including skin and soft tissue infections, but it is less commonly associated with catheter-related infections than S. epidermidis.
**Clinical Pearl / High-Yield Fact**
To reduce the risk of catheter-related infections, it is essential to follow proper insertion and maintenance techniques, including using sterile gloves, antiseptic skin preparation, and minimizing the duration of catheter use.
**Correct Answer:** C. Staphylococcus epidermidis