28-year-old woman presents to the doctor's office complaining of 2 days of itchy vaginal discharge. One week ago, she was treated for a urinary tract infection with sulfamethoxazole and trimethoprim. She completed her medication as ordered and developed the vaginal discharge shortly after. She denies abdominal pain, and her dysuria has resolved. She is not currently taking any medications. On examination, she is comfortable, appearing and has normal vital signs. Her general physical examination is normal. A pelvic examination reveals thick, curd-like, white discharge in her vagina. There is no cervical discharge or tenderness. Diagnose this patient. What caused the patient's illness? Where did the patient acquire the organism causing her symptoms? What treatment should the patient receive?