Model released. Laboratory technician using a light microscope to examine preparations derived from vaginal swabs in order to detect possible causes of infections. Microscope slides can be seen at left and right. Vaginal infections may be caused by bacteria such as gonococci, staphylococci and Gardnerella vaginalis and also by fungi such as Candida albicans. The infection may cause a vaginal, malodorous discharge occasionally stained with blood.