A 16-year-old female comes to the physician because of an increased vaginal discharge. She developed this symptom 2 days ago. She also complains of dysuriA. She is sexually active with one paner and uses condoms intermittently. Examination reveals some erythema of the cervix but is otherwise unremarkable. A urine culture is sent which comes back negative. Sexually transmitted disease testing is performed and the patient is found to have gonorrheA. While treating this patient's gonorrhea infection, treatment must also be given for which of the following?