Which of the following causes the majority of UTIs in hospitalized patients?
**Core Concept**
The majority of urinary tract infections (UTIs) in hospitalized patients are caused by a specific type of bacteria that takes advantage of the patient's compromised immune status and the presence of medical devices such as catheters.
**Why the Correct Answer is Right**
The correct answer is **Catheter-associated UTI (CAUTI)**. CAUTIs are a leading cause of healthcare-associated infections, particularly in patients with indwelling urinary catheters. The bacteria most commonly responsible for CAUTIs are Gram-negative rods such as *Escherichia coli*, *Klebsiella pneumoniae*, and *Pseudomonas aeruginosa*. These bacteria can adhere to the catheter surface and cause a urinary tract infection, which can lead to serious complications such as sepsis and kidney damage.
**Why Each Wrong Option is Incorrect**
**Option A:** While *Escherichia coli* is a common cause of UTIs, it is not the majority cause in hospitalized patients. *E. coli* is more commonly associated with community-acquired UTIs.
**Option B:** *Staphylococcus saprophyticus* is a common cause of UTIs in young, sexually active women, but it is not the majority cause in hospitalized patients.
**Option C:** *Pseudomonas aeruginosa* is a Gram-negative rod that can cause UTIs, particularly in patients with compromised immune systems or indwelling urinary catheters. However, it is not the majority cause of UTIs in hospitalized patients.
**Clinical Pearl / High-Yield Fact**
The Centers for Disease Control and Prevention (CDC) recommend that urinary catheters be removed as soon as possible to prevent CAUTIs. Additionally, proper catheter insertion and maintenance techniques, as well as hand hygiene and aseptic technique, can help reduce the risk of CAUTIs.
**Correct Answer: C. Catheter-associated UTI (CAUTI)**