. Lack superoxide dismutase and catalase, and susceptible to the lethal effects of oxygen and oxygen radicals. . Most anaerobic infections are caused by “moderately obligate anaerobes”, and polymicrobial in nature caused by combination of anaerobes, facultative anaerobes and aerobes.
Anaerobic bacteria found in human infections
b. Gram positive
Bacteroides fragilis group Prevotella melaninogenica Fusobacterium
Veillonella b. Gram positive Peptostreptococci
colon Mouth Mouth/Colon