A sewage worker presents to the Emergency depament with fever and jaundice. Laboratory findings reveal an elevated BUN and serum creatinine suggestive of renal failure. Which of the following antiboitics is recommended?

**Core Concept**
Leptospirosis is a zoonotic infection caused by the bacterium *Leptospira*, which can be transmitted through contact with contaminated water or soil. The infection can lead to a range of symptoms, including fever, jaundice, and renal failure.

**Why the Correct Answer is Right**
The recommended treatment for leptospirosis involves the use of penicillin or doxycycline. Penicillin works by inhibiting cell wall synthesis in the bacteria, leading to bacterial lysis and death. In severe cases of leptospirosis, particularly those involving renal failure, penicillin is the preferred treatment due to its ability to penetrate into the renal tubules and effectively eliminate the bacteria.

**Why Each Wrong Option is Incorrect**
**Option A:** Ciprofloxacin is a fluoroquinolone antibiotic, which may not be effective against *Leptospira* due to its resistance to fluoroquinolones.
**Option B:** Amoxicillin/clavulanate is a broad-spectrum antibiotic, but it is not the first-line treatment for leptospirosis.
**Option C:** Vancomycin is a glycopeptide antibiotic, which is primarily used to treat infections caused by Gram-positive bacteria, not *Leptospira*.

**Clinical Pearl / High-Yield Fact**
Leptospirosis can be prevented through vaccination, particularly for individuals who work with animals or in environments where exposure to contaminated water is high.

**Correct Answer:** C. Penicillin G.

✓ Correct Answer: D. Penicillin G