12th May 2024

A 25-year-old woman presents to the clinic with a complaint of vaginal discomfort and an unpleasant fishy odour, especially after sexual intercourse.

A 25-year-old woman presents to the clinic with a complaint of vaginal discomfort and an unpleasant fishy odour, especially after sexual intercourse. She denies any pain, itching, or burning sensation during urination. On examination, there is a thin greyish discharge, and the vaginal pH is found to be elevated. A whiff test with potassium hydroxide produces a strong fishy odour.

Which underlying mechanism is most likely responsible for her clinical presentation?