Review Question - QID 214220

A 23-year-old woman presents to her primary care physician with complaints of painful urination. She describes the pain as burning and is unable to void completely secondary to the pain. She denies fevers, abdominal or back pain, and bleeding. She did note a clear, odorless discharge for 2 days prior to her last menstrual period 1 week ago. She is currently sexually active with multiple partners and uses protection occasionally. She has a history of social anxiety disorder, and her current medications include sertraline and oral contraceptives. Her temperature is 99.0°F (37.2°C), blood pressure is 100/65 mmHg, pulse is 60/min, and respirations are 17/min. On exam, her abdomen is soft and nontender, and there is no costovertebral angle tenderness. There are no introital lesions, and the cervix is pink with minimal clear discharge. There is no adnexal or cervical motion tenderness. The rest of the exam is unremarkable. Urinalysis results are shown below:

Urine:
Protein: Negative
Glucose: Negative
White blood cell (WBC) count: 30/hpf
Bacteria: Many
Leukocyte esterase: Positive
Nitrites: Positive

A drug with which of the following mechanisms of action would be the most appropriate treatment?