The common organism isolated in Emphysematous pyelonephritis is –
**Core Concept**
Emphysematous pyelonephritis is a severe infection of the kidney characterized by the presence of gas in the renal parenchyma. This condition is typically seen in patients with diabetes mellitus and is associated with high morbidity and mortality. The underlying principle being tested is the identification of the common causative organism.
**Why the Correct Answer is Right**
The most common organism isolated in Emphysematous pyelonephritis is **Escherichia coli** (E. coli), a gram-negative bacterium. E. coli is a common cause of urinary tract infections, particularly in patients with diabetes, due to its ability to adhere to the uroepithelial cells and produce various virulence factors.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because while other organisms can cause urinary tract infections, they are less commonly associated with Emphysematous pyelonephritis.
**Option B:** Incorrect as it is not the most common organism isolated in Emphysematous pyelonephritis.
**Option C:** Incorrect because, although it can cause urinary tract infections, it is not the primary organism associated with this condition.
**Clinical Pearl / High-Yield Fact**
Emphysematous pyelonephritis is a medical emergency requiring prompt diagnosis and treatment. The presence of gas in the renal parenchyma is a distinctive feature of this condition, and **E. coli** is the most common causative organism.
**Correct Answer:** D. Escherichia coli.