Which of the following gram-positive organism is most common cause of UTI among sexually active women
💡 Explanation
**Core Concept**
The question is testing knowledge of the common gram-positive pathogens responsible for urinary tract infections (UTIs), particularly in sexually active women. The correct answer is related to the bacteriology of UTIs and the epidemiology of UTIs in this demographic.
**Why the Correct Answer is Right**
The most common gram-positive organism causing UTIs among sexually active women is **Enterococcus faecalis**. However, this is not the correct answer in this case. The correct answer is actually **Staphylococcus saprophyticus**. This organism is a common cause of UTIs in sexually active young women due to its ability to adhere to the bladder epithelium and cause infection. The pathogenesis involves the production of surface proteins that facilitate adhesion and biofilm formation.
**Why Each Wrong Option is Incorrect**
* **Option A:** While Enterococcus faecalis is a gram-positive organism that can cause UTIs, it is more commonly associated with healthcare-associated infections and not typically the most common cause of UTIs in sexually active women.
* **Option B:** Staphylococcus aureus is a gram-positive organism that can cause UTIs, but it is not the most common cause of UTIs in sexually active women.
* **Option C:** This option is missing, please provide the complete question.
**Clinical Pearl / High-Yield Fact**
Staphylococcus saprophyticus is the second most common cause of UTIs in young women, accounting for approximately 10-15% of cases. It is often associated with sexual activity and can cause symptoms similar to those of Escherichia coli, the most common cause of UTIs.