A 58-year-old man with a history of diet-controlled type 2 diabetes mellitus is evaluated in the hospital on day 3 of admission. He initially presented with progressive left lower quadrant abdominal pain, nausea, and low-grade fever. Computed tomography of the abdomen and pelvis demonstrated inflammation of the sigmoid colon with surrounding fat stranding, consistent with acute uncomplicated diverticulitis. He was admitted and started on empiric intravenous piperacillin-tazobactam. Currently, his temperature is 37.1°C (98.8°F), his abdominal pain has largely resolved, and he is tolerating a regular diet. Blood cultures drawn on admission have grown *Escherichia coli* and *Bacteroides fragilis*. Susceptibility testing reveals that both isolates are susceptible to amoxicillin-clavulanate, ertapenem, and piperacillin-tazobactam. The *E. coli* isolate demonstrates high-level resistance to ciprofloxacin and levofloxacin. Based on these findings, which of the following is the most appropriate next step in pharmacotherapy?
- Transition to oral amoxicillin-clavulanateCevap
- BTransition to oral ciprofloxacin and metronidazole
- CContinue intravenous piperacillin-tazobactam
- DTransition to oral cephalexin and metronidazole
- EAdd intravenous vancomycin to the current regimen