Most anaerobic infections are pyogenic and arise from the normal flora of the skin, oropharynx,

the large intestine, or the female genital tract. Such infections typically involve multiple species

of bacteria, some strict anaerobes, some strict aerobes and others that are facultative anaerobes

(i.e., able to grow aerobically or anaerobically). The polymicrobial nature of infections involving

anaerobic bacteria is apparent in infections of the respiratory tract, abdomen, pelvis, and soft

tissue, where the number of isolates in an infectious site varies between two and five (1-3). The

contributing role of anaerobes in these infections has been often questioned (4).