A 21-Year-Old Female College Student Comes to the Physician Because

A 21-year-old female college student comes to the physician because of a 2-week history of vaginal itching and burning. She also noticed white vaginal discharge despite cleaning her genital area daily using a "soap-free, natural" vaginal douche. She is worried that she might have contracted a sexually transmitted disease after meeting her new boyfriend around one month ago. She has type 1 diabetes mellitus. She had an intrauterine device implanted 3 months ago and does not use barrier protection. She smokes one pack of cigarettes per day and does not drink alcohol. Pelvic examination shows an erythematous vulva and a thick white discharge that adheres to the vaginal wall.  The rest of the physical examination is normal.  Microscopic examination reveals budding cells.  Which of the following is the most likely underlying cause of her current condition?

A) Decreased glycogen concentration in the vaginal epithelium
B) Decreased number of gram-positive bacteria in the vagina
C) Decreased thickness of the vaginal epithelium
D) Increased alkaline secretions by the cervical mucosa
E) Viral DNA incorporation into lower genital epithelia