Drug of choice for infection by Gardnerella vaginatis is

Ans is 'b' ie Metronidazole (Ref. Harrisons, 16/e, p 767 (15/e, p 843))Gardnerella vaginalis causes Bacterial vaginosis*.Bacterial vaginosis can be differentiated from other vaginitis and diagnosed by Amsel criteria :White homogenous vaginal discharge*Vaginal discharges pH > 4.5*Liberation of distinct fishy odour* on mixing vaginal discharge with 10% solution of KOH.Microscopic demonstration of clue cells* (Vaginal epithelial cells coated with coccobacillary organisms)