Final answer:
Clue cells are vaginal epithelial cells that can be examined to determine the presence of Gardnerella vaginalis. They have a unique appearance caused by bacterial cells attached to their surface. A shift in predominance from gram-positive bacilli to clue cells can indicate bacterial vaginosis.
Step-by-step explanation:
Vaginal epithelial cells that can be examined to determine the presence of Gardnerella vaginalis are referred to as clue cells. These cells have a unique appearance caused by the presence of bacteria on their surface. By examining slides prepared from vaginal swabs, it is possible to distinguish clue cells from other types of cells. Clue cells are indicative of bacterial vaginosis, a condition caused by an overgrowth of G. vaginalis.