Cervical bacteria. Coloured scanning electron micrograph (SEM) of cultured bacteria from the cervix. A healthy cervical flora protects the body against urogenital infections. It is made up of many different types of bacteria, the predominant bacteria being lactobacilli. These beneficial or "good" bacteria play a key role in defending against infection. Lactobacilli provide protection against microbes from the external environment, as well as microbes that reside in the cervix but multiply abnormally quickly, causing cervicitis. Magnification: x3000 when printed at 10 centimetres wide.