Light micrograph of a vaginal smear showing the rod-shaped bacteria Lactobacillus acidophilus, which forms the predominant flora in the vagina of the sexually mature human female. These bacteria ferment lactic acid from the glycogen in the epithelial lining of the vagina. The acidic environment that they produce, and live in, inhibits the growth of many other bacterial forms & as such protects the vaginal passageway from infection. Lactobacillus is a non-sporing, Gram positive bacteria commonly found growing in chains. Magnification: X 250 at 35mm size.