**Core Concept**
The patient's clinical presentation and microbiological findings suggest a diagnosis of burn wound sepsis caused by Pseudomonas aeruginosa, a gram-negative, oxidase-positive bacillus that does not ferment sugars. Pseudomonas aeruginosa is a common pathogen in burn wounds, particularly in patients with large body surface area burns and compromised skin integrity.

**Why the Correct Answer is Right**
Pseudomonas aeruginosa is a notorious cause of burn wound sepsis due to its ability to form biofilms, which protect it from antibiotics and host immune responses. The organism's production of elastase, pyocyanin, and other virulence factors contributes to its pathogenicity. In this case, the patient's clinical presentation of fever, leukocytosis, erythema, and swelling around the wound, along with the laboratory findings of gram-negative, oxidase-positive bacilli that do not ferment sugars, is consistent with Pseudomonas aeruginosa infection.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Pseudomonas aeruginosa is not typically susceptible to first-generation cephalosporins, which are often used to treat other types of bacterial infections.
**Option B:** This option is incorrect because while fluoroquinolones have broad-spectrum activity, they are not the drug of choice for Pseudomonas aeruginosa infections due to concerns about resistance and limited efficacy in burn wound sepsis.
**Option C:** This option is incorrect because while beta-lactam/beta-lactamase inhibitor combinations can be effective against some gram-negative bacteria, they are not the preferred choice for Pseudomonas aeruginosa infections in burn wound sepsis.

**Clinical Pearl / High-Yield Fact**
In burn wound sepsis, early recognition and treatment of Pseudomonas aeruginosa infection are critical to preventing morbidity and mortality. A high index of suspicion should be maintained for patients with large body surface area burns, particularly if they develop fever, leukocytosis, and signs of wound infection.

**Correct Answer: C. Ciprofloxacin**